mm/damon/sysfs-schemes: decouple from damos_action

mm/damon/sysfs-schemes: decouple from damos_action

Decouple DAMOS sysfs interface from damos_action.  For this, define and
use new sysfs-schemes internal data structure that maps the user-space
keywords and damos_action, instead of having the implicit and unflexible
array index rule.

[akpm@linux-foundation.org: make damos_sysfs_action_names static]
  Closes: https://lore.kernel.org/oe-kbuild-all/202506271655.b8yfEZIT-lkp@intel.com/
Link: https://lkml.kernel.org/r/20250622213759.50930-3-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>