mm_zone: Generalise has_managed_dma()

mm_zone: Generalise has_managed_dma()

It would be useful to be able to check for potential DMA pages beyond
just ZONE_DMA - generalise the existing has_managed_dma() function to
allow checking other zones too.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Acked-by: David Hildenbrand (Red Hat) <david@kernel.org>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Tested-by: Vladimir Kondratiev <vladimir.kondratiev@mobileye.com>
Reviewed-by: Baoquan He <bhe@redhat.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Link: https://lore.kernel.org/r/bd002d2351074e57be1ca08f03f333debac658fb.1768230104.git.robin.murphy@arm.com