mm/damon/core: update kernel-doc comments for DAMOS filters supports of each DAMON operations set

Supports of each DAMOS filter type are up to DAMON operations set
implementation in use, but not well mentioned on the kernel-doc comments. 
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Link: https://lkml.kernel.org/r/20230110190400.119388-3-sj@kernel.orgSigned-off-by: SeongJae Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

include/linux/damon.h

@@ -227,6 +227,11 @@ struct damos_stat {
  * @DAMOS_FILTER_TYPE_ANON:	Anonymous pages.
  * @DAMOS_FILTER_TYPE_MEMCG:	Specific memcg's pages.
  * @NR_DAMOS_FILTER_TYPES:	Number of filter types.
+ *
+ * The support of each filter type is up to running &struct damon_operations.
+ * &enum DAMON_OPS_PADDR is supporting all filter types, while
+ * &enum DAMON_OPS_VADDR and &enum DAMON_OPS_FVADDR are not supporting any
+ * filter types.
  */
 enum damos_filter_type {
 	DAMOS_FILTER_TYPE_ANON,