DAMON debugfs interface is deprecated.  The fact has documented by commit
5445fcbc ("Docs/admin-guide/mm/damon/usage: add DAMON debugfs
interface deprecation notice").  Commit 620932cd ("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
eb07c4f3 ("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.orgSigned-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>