drm/malidp: Use struct drm_gem_object_funcs.get_sg_table internally

The malidp driver uses GEM object functions for callbacks. Fix it to
use them internally as well.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Daniel Vetter <daniel@ffwll.ch>
Fixes: ecdd6474 ("drm/malidp: Use GEM CMA object functions")
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Emil Velikov <emil.velikov@collabora.com>
Cc: Liviu Dudau <liviu.dudau@arm.com>
Cc: Brian Starkey <brian.starkey@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200807111022.12117-1-tzimmermann@suse.de

drivers/gpu/drm/arm/malidp_planes.c

@@ -346,7 +346,7 @@ static bool malidp_check_pages_threshold(struct malidp_plane_state *ms,
 		if (cma_obj->sgt)
 			sgt = cma_obj->sgt;
 		else
-			sgt = obj->dev->driver->gem_prime_get_sg_table(obj);
+			sgt = obj->funcs->get_sg_table(obj);
 
 		if (!sgt)
 			return false;