MAINTAINERS: add missing files to page alloc section

There are a couple of mm/-specific header files that were accidentally
missed previously, and some page ref debug code also that ought to live
here.

Link: https://lkml.kernel.org/r/20250722174143.147143-1-lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Acked-by: Zi Yan <ziy@nvidia.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Christoph Lameter (Ampere) <cl@gentwo.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Jann Horn <jannh@google.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nico Pache <npache@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Tejun Heo <tj@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Joshua Hahn <joshua.hahnjy@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Author: ljskernel

MAINTAINERS

@@ -15880,6 +15880,7 @@ F:	include/linux/gfp.h
 F:	include/linux/page-isolation.h
 F:	mm/compaction.c
 F:	mm/debug_page_alloc.c
+F:	mm/debug_page_ref.c
 F:	mm/fail_page_alloc.c
 F:	mm/page_alloc.c
 F:	mm/page_ext.c
@@ -15888,8 +15889,10 @@ F:	mm/page_isolation.c
 F:	mm/page_owner.c
 F:	mm/page_poison.c
 F:	mm/page_reporting.c
+F:	mm/page_reporting.h
 F:	mm/show_mem.c
 F:	mm/shuffle.c
+F:	mm/shuffle.h
 
 MEMORY MANAGEMENT - RECLAIM
 M:	Andrew Morton <akpm@linux-foundation.org>