Renamed config -> cfg

Note this includes both the lfs3_config -> lfs3_cfg structs as well as
the LFS3_CONFIG -> LFS3_CFG include define:

- LFS3_CONFIG -> LFS3_CFG
- struct lfs3_config -> struct lfs3_cfg
- struct lfs3_file_config -> struct lfs3_file_cfg
- struct lfs3_*bd_config -> struct lfs3_*bd_cfg
- cfg -> cfg

We were already using cfg as the variable name everywhere. The fact that
these names were different was an inconsistency that should be fixed
since we're committing to an API break.

LFS3_CFG is already out-of-date from upstream, and there's plans for a
config rework, but I figured I'd go ahead and change it as well to lower
the chances it gets overlooked.

---

Note this does _not_ affect LFS3_TAG_CONFIG. Having the on-disk vs
driver-level config take slightly different names is not a bad thing.

lfs3.c

@@ -11585,7 +11585,7 @@ static inline lfs3_off_t lfs3_file_size_(const lfs3_file_t *file) {
 // file operations
 
 static void lfs3_file_init(lfs3_file_t *file, uint32_t flags,
-        const struct lfs3_file_config *cfg) {
+        const struct lfs3_file_cfg *cfg) {
     file->cfg = cfg;
     file->b.h.flags = lfs3_o_typeflags(LFS3_TYPE_REG) | flags;
     #ifndef LFS3_KVONLY
@@ -11672,7 +11672,7 @@ static int lfs3_file_ck(lfs3_t *lfs3, const lfs3_file_t *file,
 
 int lfs3_file_opencfg_(lfs3_t *lfs3, lfs3_file_t *file,
         const char *path, uint32_t flags,
-        const struct lfs3_file_config *cfg) {
+        const struct lfs3_file_cfg *cfg) {
     #ifndef LFS3_RDONLY
     if (!lfs3_o_isrdonly(flags)) {
         // prepare our filesystem for writing
@@ -11857,7 +11857,7 @@ failed:;
 
 int lfs3_file_opencfg(lfs3_t *lfs3, lfs3_file_t *file,
         const char *path, uint32_t flags,
-        const struct lfs3_file_config *cfg) {
+        const struct lfs3_file_cfg *cfg) {
     // already open?
     LFS3_ASSERT(!lfs3_handle_isopen(lfs3, &file->b.h));
     // don't allow the forbidden mode!
@@ -11897,7 +11897,7 @@ int lfs3_file_opencfg(lfs3_t *lfs3, lfs3_file_t *file,
 }
 
 // default file config
-static const struct lfs3_file_config lfs3_file_defaultcfg = {0};
+static const struct lfs3_file_cfg lfs3_file_defaultcfg = {0};
 
 int lfs3_file_open(lfs3_t *lfs3, lfs3_file_t *file,
         const char *path, uint32_t flags) {
@@ -14180,7 +14180,7 @@ int lfs3_file_ckdata(lfs3_t *lfs3, lfs3_file_t *file) {
 // advanced file operations
 
 // kv file config, we need to explicitly disable the file cache
-static const struct lfs3_file_config lfs3_file_kvconfig = {
+static const struct lfs3_file_cfg lfs3_file_kvcfg = {
     // TODO is this the best way to do this?
     .cache_buffer = (uint8_t*)1,
     .cache_size = 0,
@@ -14192,7 +14192,7 @@ lfs3_ssize_t lfs3_get(lfs3_t *lfs3, const char *path,
     // bypass the cache
     lfs3_file_t file;
     int err = lfs3_file_opencfg(lfs3, &file, path, LFS3_O_RDONLY,
-            &lfs3_file_kvconfig);
+            &lfs3_file_kvcfg);
     if (err) {
         return err;
     }
@@ -14216,7 +14216,7 @@ lfs3_ssize_t lfs3_size(lfs3_t *lfs3, const char *path) {
     // bypass the cache
     lfs3_file_t file;
     int err = lfs3_file_opencfg(lfs3, &file, path, LFS3_O_RDONLY,
-            &lfs3_file_kvconfig);
+            &lfs3_file_kvcfg);
     if (err) {
         return err;
     }
@@ -14244,7 +14244,7 @@ int lfs3_set(lfs3_t *lfs3, const char *path,
     //   normally in lfs3_file_close, lfs3_file_sync has its own logic
     //   to try to commit small files atomically
     //
-    struct lfs3_file_config cfg = {
+    struct lfs3_file_cfg cfg = {
         .cache_buffer = (uint8_t*)buffer,
         .cache_size = size,
     };
@@ -14271,7 +14271,7 @@ static int lfs3_deinit(lfs3_t *lfs3);
 
 // initialize littlefs state, assert on bad configuration
 static int lfs3_init(lfs3_t *lfs3, uint32_t flags,
-        const struct lfs3_config *cfg) {
+        const struct lfs3_cfg *cfg) {
     // unknown flags?
     LFS3_ASSERT((flags & ~(
             LFS3_IFDEF_RDONLY(0, LFS3_M_RDWR)
@@ -15130,7 +15130,7 @@ static int lfs3_fs_gc_(lfs3_t *lfs3, lfs3_trv_t *trv,
         uint32_t flags, lfs3_soff_t steps);
 
 int lfs3_mount(lfs3_t *lfs3, uint32_t flags,
-        const struct lfs3_config *cfg) {
+        const struct lfs3_cfg *cfg) {
     #ifdef LFS3_YES_RDONLY
     flags |= LFS3_M_RDONLY;
     #endif
@@ -15366,7 +15366,7 @@ static int lfs3_formatinited(lfs3_t *lfs3) {
 
 #ifndef LFS3_RDONLY
 int lfs3_format(lfs3_t *lfs3, uint32_t flags,
-        const struct lfs3_config *cfg) {
+        const struct lfs3_cfg *cfg) {
     #ifdef LFS3_YES_REVDBG
     flags |= LFS3_F_REVDBG;
     #endif