drm/atmel-hlcdc: 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: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1500837417-40580-7-git-send-email-noralf@tronnes.org

drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c

@@ -761,8 +761,6 @@ static struct drm_driver atmel_hlcdc_dc_driver = {
 	.gem_prime_vunmap = drm_gem_cma_prime_vunmap,
 	.gem_prime_mmap = drm_gem_cma_prime_mmap,
 	.dumb_create = drm_gem_cma_dumb_create,
-	.dumb_map_offset = drm_gem_cma_dumb_map_offset,
-	.dumb_destroy = drm_gem_dumb_destroy,
 	.fops = &fops,
 	.name = "atmel-hlcdc",
 	.desc = "Atmel HLCD Controller DRM",