mm/damon/paddr: support only damos->ops_filters

mm/damon/paddr: support only damos->ops_filters

DAMON physical address space operation set implementation (paddr) started
handling both damos->filters and damos->ops_filters to avoid breakage
during the change for the ->ops_filters setup.  Now the change is done, so
paddr's support of ->filters is only a waste that can safely be dropped.
Remove it.

Link: https://lkml.kernel.org/r/20250304211913.53574-6-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>