drm/vmwgfx: Enable FB_DAMAGE_CLIPS property for SOU primary plane

SOU primary plane now support damage clips, enable it for user-space.

Signed-off-by: Deepak Rawat <drawat@vmware.com>
Reviewed-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>