mm/damon/sysfs-schemes: decouple from damos_quota_goal_metric

mm/damon/sysfs-schemes: decouple from damos_quota_goal_metric

Patch series "mm/damon: decouple sysfs from core".

DAMON sysfs interface is coupled with core layer.  It maintains some of
its keywords arrays be synchronized with matching DAMON core API enums.
It is unnecessary coupling that makes separated changes for different
layers difficult.  Decouple the layers by introducing new data structure
for the mappings on DAMON sysfs interface.

This patch (of 5):

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

Link: https://lkml.kernel.org/r/20250622213759.50930-1-sj@kernel.org
Link: https://lkml.kernel.org/r/20250622213759.50930-2-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>