MAINTAINERS: add memory advice section

The madvise code straddles both VMA and page table manipulation.  As a
result, separate it out into its own section and add maintainers/reviewers
as appropriate.

We additionally include the mman-common.h file as this contains the shared
madvise flags and it is important we maintain this alongside madvise.c.

Link: https://lkml.kernel.org/r/20250411072724.10841-1-lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Acked-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Jann Horn <jannh@google.com>
Acked-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Author: lorenzo-stoakes

MAINTAINERS

@@ -15573,6 +15573,20 @@ F:	mm/vma.h
 F:	mm/vma_internal.h
 F:	tools/testing/vma/
 
+MEMORY MAPPING - MADVISE (MEMORY ADVICE)
+M:	Andrew Morton <akpm@linux-foundation.org>
+M:	Liam R. Howlett <Liam.Howlett@oracle.com>
+M:	Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
+M:	David Hildenbrand <david@redhat.com>
+R:	Vlastimil Babka <vbabka@suse.cz>
+R:	Jann Horn <jannh@google.com>
+L:	linux-mm@kvack.org
+S:	Maintained
+W:	http://www.linux-mm.org
+T:	git git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
+F:	include/uapi/asm-generic/mman-common.h
+F:	mm/madvise.c
+
 MEMORY TECHNOLOGY DEVICES (MTD)
 M:	Miquel Raynal <miquel.raynal@bootlin.com>
 M:	Richard Weinberger <richard@nod.at>