drm/ast: Request PCI BAR with devres

drm/ast: Request PCI BAR with devres

ast currently ioremaps two PCI BARs using pcim_iomap(). It does not perform
a request on the regions, however, which would make the driver a bit more
robust.

PCI now offers pcim_iomap_region(), a managed function which both requests
and ioremaps a BAR.

Replace pcim_iomap() with pcim_iomap_region().

Suggested-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://lore.kernel.org/r/20240807083018.8734-4-pstanner@redhat.com
Signed-off-by: Philipp Stanner <pstanner@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Dave Airlie <airlied@redhat.com>