[SPARC]: Respect vm_page_prot in io_remap_page_range().

Make sure the callers do a pgprot_noncached() on
vma->vm_page_prot.

Pointed out by Hugh Dickens.

Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/char/drm/drm_vm.c b/drivers/char/drm/drm_vm.c
index 0291cd6..ffd0800 100644
--- a/drivers/char/drm/drm_vm.c
+++ b/drivers/char/drm/drm_vm.c
@@ -619,6 +619,7 @@
 #endif
 		offset = dev->driver->get_reg_ofs(dev);
 #ifdef __sparc__
+		vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
 		if (io_remap_pfn_range(DRM_RPR_ARG(vma) vma->vm_start,
 				       (map->offset + offset) >> PAGE_SHIFT,
 				       vma->vm_end - vma->vm_start,