mm/damon: rename CONFIG_DAMON_DBGFS to DAMON_DBGFS_DEPRECATED

DAMON debugfs interface is deprecated.  The fact has documented by commit
5445fcbc4c ("Docs/admin-guide/mm/damon/usage: add DAMON debugfs
interface deprecation notice").  Commit 620932cd28 ("mm/damon/dbgfs:
print DAMON debugfs interface deprecation message") further started
printing a warning message when users still use it.  Many people don't
read documentation or kernel log, though.

Make the deprecation harder to be ignored using the approach of commit
eb07c4f39c ("mm/slab: rename CONFIG_SLAB to CONFIG_SLAB_DEPRECATED"). 
'make oldconfig' with 'CONFIG_DAMON_DBGFS=y' will get a new prompt with
the explicit deprecation notice on the name.  'make olddefconfig' with
'CONFIG_DAMON_DBGFS=y' will result in not building DAMON debugfs
interface.  If there is a real user of DAMON debugfs interface, they will
complain the change to the builder.

Link: https://lkml.kernel.org/r/20240130013549.89538-3-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Alex Shi <alexs@kernel.org>
Cc: Hu Haowen <2023002089@link.tyut.edu.cn>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Yanteng Si <siyanteng@loongson.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm/damon/Kconfig

@@ -71,7 +71,7 @@ config DAMON_SYSFS_KUNIT_TEST
 
 	  If unsure, say N.
 
-config DAMON_DBGFS
+config DAMON_DBGFS_DEPRECATED
 	bool "DAMON debugfs interface (DEPRECATED!)"
 	depends on DAMON_VADDR && DAMON_PADDR && DEBUG_FS
 	help
@@ -84,6 +84,11 @@ config DAMON_DBGFS
 	  (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
+	bool
+	default y
+	depends on DAMON_DBGFS_DEPRECATED
+
 config DAMON_DBGFS_KUNIT_TEST
 	bool "Test for damon debugfs interface" if !KUNIT_ALL_TESTS
 	depends on DAMON_DBGFS && KUNIT=y