mm: cma: constify and use correct signness in mm/cma.c

mm: cma: constify and use correct signness in mm/cma.c

Constify function parameters and use correct signness where needed.

Signed-off-by: Sasha Levin <[email protected]>
Cc: Michal Nazarewicz <[email protected]>
Cc: Marek Szyprowski <[email protected]>
Cc: Joonsoo Kim <[email protected]>
Cc: Laurent Pinchart <[email protected]>
Acked-by: Gregory Fong <[email protected]>
Cc: Pintu Kumar <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>