DAMON_RECLAIM and DAMON_LRU_SORT have module parameters for watermarks
that having same names.  This commit implements a macro for generating
such module parameters so that we can reuse later.

Link: https://lkml.kernel.org/r/20220913174449.50645-13-sj@kernel.orgSigned-off-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>