drm/zte: Use .dumb_map_offset and .dumb_destroy defaults

This driver can use the drm_driver.dumb_destroy and
drm_driver.dumb_map_offset defaults, so no need to set them.

Cc: Shawn Guo <shawnguo@kernel.org>
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Acked-by: Shawn Guo <shawnguo@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/1500837417-40580-21-git-send-email-noralf@tronnes.org

drivers/gpu/drm/zte/zx_drm_drv.c

@@ -62,8 +62,6 @@ static struct drm_driver zx_drm_driver = {
 	.gem_free_object_unlocked = drm_gem_cma_free_object,
 	.gem_vm_ops = &drm_gem_cma_vm_ops,
 	.dumb_create = drm_gem_cma_dumb_create,
-	.dumb_map_offset = drm_gem_cma_dumb_map_offset,
-	.dumb_destroy = drm_gem_dumb_destroy,
 	.prime_handle_to_fd = drm_gem_prime_handle_to_fd,
 	.prime_fd_to_handle = drm_gem_prime_fd_to_handle,
 	.gem_prime_export = drm_gem_prime_export,