drm/rockchip: Use cma gem vm ops

No need to reinvent this little wheel.

v2: Like, try to make it compile even.

Cc: Mark Yao <mark.yao@rock-chips.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1464630800-30786-21-git-send-email-daniel.vetter@ffwll.ch

drivers/gpu/drm/rockchip/rockchip_drm_drv.c

@@ -19,6 +19,7 @@
 #include <drm/drmP.h>
 #include <drm/drm_crtc_helper.h>
 #include <drm/drm_fb_helper.h>
+#include <drm/drm_gem_cma_helper.h>
 #include <linux/dma-mapping.h>
 #include <linux/pm_runtime.h>
 #include <linux/module.h>
@@ -300,11 +301,6 @@ static const struct file_operations rockchip_drm_driver_fops = {
 	.release = drm_release,
 };
 
-const struct vm_operations_struct rockchip_drm_vm_ops = {
-	.open = drm_gem_vm_open,
-	.close = drm_gem_vm_close,
-};
-
 static struct drm_driver rockchip_drm_driver = {
 	.driver_features	= DRIVER_MODESET | DRIVER_GEM |
 				  DRIVER_PRIME | DRIVER_ATOMIC,
@@ -315,7 +311,7 @@ static struct drm_driver rockchip_drm_driver = {
 	.get_vblank_counter	= drm_vblank_no_hw_counter,
 	.enable_vblank		= rockchip_drm_crtc_enable_vblank,
 	.disable_vblank		= rockchip_drm_crtc_disable_vblank,
-	.gem_vm_ops		= &rockchip_drm_vm_ops,
+	.gem_vm_ops		= &drm_gem_cma_vm_ops,
 	.gem_free_object_unlocked = rockchip_gem_free_object,
 	.dumb_create		= rockchip_gem_dumb_create,
 	.dumb_map_offset	= rockchip_gem_dumb_map_offset,