mm: introduce memdesc_is_zone_device()

Remove the conversion from folio to page in folio_is_zone_device() by
introducing memdesc_is_zone_device() which takes a memdesc_flags_t from
either a page or a folio.

Link: https://lkml.kernel.org/r/20250805172307.1302730-8-willy@infradead.org


Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>