mm/damon/Kconfig: add DAMON debugfs interface deprecation notice

DAMON debugfs interface has announced to be deprecated after >v5.15 LTS
kernel is released.  And, v6.1.y has announced to be an LTS[1].

Though the announcement was there for a while, some people might not
noticed that so far.  Also, some users could depend on it and have
problems at  movng to the alternative (DAMON sysfs interface).

For such cases, note DAMON debugfs interface as deprecated, and contacts
to ask helps on the Kconfig.

[1] https://git.kernel.org/pub/scm/docs/kernel/website.git/commit/?id=332e9121320bc7461b2d3a79665caf153e51732c

Link: https://lkml.kernel.org/r/20230209192009.7885-3-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>

mm/damon/Kconfig

@@ -60,16 +60,17 @@ config DAMON_SYSFS
 	  the interface for arbitrary data access monitoring.
 
 config DAMON_DBGFS
-	bool "DAMON debugfs interface"
+	bool "DAMON debugfs interface (DEPRECATED!)"
 	depends on DAMON_VADDR && DAMON_PADDR && DEBUG_FS
 	help
 	  This builds the debugfs interface for DAMON.  The user space admins
 	  can use the interface for arbitrary data access monitoring.
 
 	  If unsure, say N.
 
-	  This will be removed after >5.15.y LTS kernel is released, so users
-	  should move to the sysfs interface (DAMON_SYSFS).
+	  This is deprecated, so users should move to the sysfs interface
+	  (DAMON_SYSFS).  If you depend on this and cannot move, please report
+	  your usecase to damon@lists.linux.dev and linux-mm@kvack.org.
 
 config DAMON_DBGFS_KUNIT_TEST
 	bool "Test for damon debugfs interface" if !KUNIT_ALL_TESTS