drm/vram-helper: Drop drm_gem_prime_export/import

They're the default.

Aside: Would be really nice to switch the others over to
drm_gem_object_funcs.

Reviewed-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <maxime.ripard@bootlin.com>
Cc: Sean Paul <sean@poorly.run>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190614203615.12639-41-daniel.vetter@ffwll.ch

include/drm/drm_gem_vram_helper.h

@@ -142,8 +142,6 @@ int drm_gem_vram_driver_gem_prime_mmap(struct drm_gem_object *obj,
 				       struct vm_area_struct *vma);
 
 #define DRM_GEM_VRAM_DRIVER_PRIME \
-	.gem_prime_export = drm_gem_prime_export, \
-	.gem_prime_import = drm_gem_prime_import, \
 	.gem_prime_pin	  = drm_gem_vram_driver_gem_prime_pin, \
 	.gem_prime_unpin  = drm_gem_vram_driver_gem_prime_unpin, \
 	.gem_prime_vmap	  = drm_gem_vram_driver_gem_prime_vmap, \