mm/mglru: add dummy pmd_dirty()

Add dummy pmd_dirty() for architectures that don't provide it.
This is similar to commit 6617da8f

 ("mm: add dummy pmd_young()
for architectures not having it").

Link: https://lkml.kernel.org/r/20231227141205.2200125-5-kinseyho@google.com
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202312210606.1Etqz3M4-lkp@intel.com/
Closes: https://lore.kernel.org/oe-kbuild-all/202312210042.xQEiqlEh-lkp@intel.com/
Signed-off-by: Kinsey Ho <kinseyho@google.com>
Suggested-by: Yu Zhao <yuzhao@google.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Donet Tom <donettom@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>