mm: kmemleak: add rbtree and store physical address for objects allocated with PA

Add object_phys_tree_root to store the objects allocated with physical
address.  Distinguish it from object_tree_root by OBJECT_PHYS flag or
function argument.  The physical address is stored directly in those
objects.

Link: https://lkml.kernel.org/r/20220611035551.1823303-4-patrick.wang.shcn@gmail.comSigned-off-by: Patrick Wang <patrick.wang.shcn@gmail.com>
Suggested-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Yee Lee <yee.lee@mediatek.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>