mm/damon/sysfs: use damon_addr_range for region's start and end values

DAMON has a struct for each address range but DAMON sysfs interface is
using the low type (unsigned long) for storing the start and end addresses
of regions.  Use the dedicated struct for better type safety.

Link: https://lkml.kernel.org/r/20221026225943.100429-6-sj@kernel.org


Signed-off-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>