mm: kmemleak: alloc gray object for reserved region with direct map

Reserved regions with direct mapping may contain references to other
regions.  CMA region with fixed location is reserved without creating
kmemleak_object for it.

So add them as gray kmemleak objects.

Link: https://lkml.kernel.org/r/20211123090641.3654006-1-calvinzhang.cool@gmail.com


Signed-off-by: Calvin Zhang <calvinzhang.cool@gmail.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>