include: kernel: doc: improve slab API "isr-ok" documentation

As discussed on Discord, certain k_mem_slab* APIs are ISR-OK, but not
marked as such. After APIs review, the following functions should be
ISR-OK:
- k_mem_slab_free
- k_mem_slab_num_used_get
- k_mem_slab_max_used_get
- k_mem_slab_num_free_get
- k_mem_slab_runtime_stats_get
- k_mem_slab_runtime_stats_reset_max

Added the Doxygen marker where needed.

Signed-off-by: Loic Domaigne <[email protected]>

Author: ljd42

include/zephyr/kernel.h

@@ -5663,6 +5663,8 @@ int k_mem_slab_alloc(struct k_mem_slab *slab, void **mem,
  * This routine releases a previously allocated memory block back to its
  * associated memory slab.
  *
+ * @funcprops \isr_ok
+ *
  * @param slab Address of the memory slab.
  * @param mem Pointer to the memory block (as returned by k_mem_slab_alloc()).
  */
@@ -5674,6 +5676,8 @@ void k_mem_slab_free(struct k_mem_slab *slab, void *mem);
  * This routine gets the number of memory blocks that are currently
  * allocated in @a slab.
  *
+ * @funcprops \isr_ok
+ *
  * @param slab Address of the memory slab.
  *
  * @return Number of allocated memory blocks.
@@ -5689,6 +5693,8 @@ static inline uint32_t k_mem_slab_num_used_get(struct k_mem_slab *slab)
  * This routine gets the maximum number of memory blocks that were
  * allocated in @a slab.
  *
+ * @funcprops \isr_ok
+ *
  * @param slab Address of the memory slab.
  *
  * @return Maximum number of allocated memory blocks.
@@ -5709,6 +5715,8 @@ static inline uint32_t k_mem_slab_max_used_get(struct k_mem_slab *slab)
  * This routine gets the number of memory blocks that are currently
  * unallocated in @a slab.
  *
+ * @funcprops \isr_ok
+ *
  * @param slab Address of the memory slab.
  *
  * @return Number of unallocated memory blocks.
@@ -5723,6 +5731,8 @@ static inline uint32_t k_mem_slab_num_free_get(struct k_mem_slab *slab)
  *
  * This routine gets the runtime memory usage stats for the slab @a slab.
  *
+ * @funcprops \isr_ok
+ *
  * @param slab Address of the memory slab
  * @param stats Pointer to memory into which to copy memory usage statistics
  *
@@ -5738,6 +5748,8 @@ int k_mem_slab_runtime_stats_get(struct k_mem_slab *slab, struct sys_memory_stat
  * This routine resets the maximum memory usage for the slab @a slab to its
  * current usage.
  *
+ * @funcprops \isr_ok
+ *
  * @param slab Address of the memory slab
  *
  * @retval 0 Success