runners: bench: Added BENCH_SIMTIME/SIMRESET/PAUSE/RESUME/etc

- BENCH_SIMTIME()   => lfs3_kiwibd_simtime()
- BENCH_SIMRESET()  => lfs3_kiwibd_simreset()
- BENCH_SIMPAUSE()  => lfs3_kiwibd_simpause()
- BENCH_SIMRESUME() => lfs3_kiwibd_simresume()
- BENCH_RESET()     => lfs3_kiwibd_simreset() + BENCH_STACK/HEAP_RESET()
- BENCH_PAUSE()     => lfs3_kiwibd_simpause() + BENCH_STACK/HEAP_PAUSE()
- BENCH_RESUME()    => lfs3_kiwibd_simresume() + BENCH_STACK/HEAP_RESUME()

This does two things:

1. Adds pause/resume counters to bd counters to make it easier to
   exclude operations from the current bench (potentially useful for
   seq+disk usage).

2. Exposes bd simtime operations as BENCH_* macros, to make it a bit
   easier to interact with simtime without tying all the benches to
   kiwibd. (Not that we'll ever probably not use kiwibd, but still).

Also adopted 32-bit counters for stack/heap pause state instead of a
32-bit stack. Not that either are at a risk of overflowing, but better
safe than sorry.

bd/lfs3_kiwibd.h

@@ -107,6 +107,8 @@ typedef struct lfs3_kiwibd {
         uint8_t *mem;
     } u;
 
+    // sim state
+    uint32_t paused;
     // amount read/progged/erased
     lfs3_kiwibd_io_t reads;
     lfs3_kiwibd_io_t progs;
@@ -161,6 +163,12 @@ lfs3_kiwibd_sns_t lfs3_kiwibd_simtime(const struct lfs3_cfg *cfg);
 // Reset simulation counters
 int lfs3_kiwibd_simreset(const struct lfs3_cfg *cfg);
 
+// Pause simulation counters
+int lfs3_kiwibd_simpause(const struct lfs3_cfg *cfg);
+
+// Resume simulation counters
+int lfs3_kiwibd_simresume(const struct lfs3_cfg *cfg);
+
 // Get total number of read transactions
 lfs3_kiwibd_sio_t lfs3_kiwibd_reads(const struct lfs3_cfg *cfg);