kernel-drm: fix thumbernail scrambled issue when IED is enabled

kernel-drm: fix thumbernail scrambled issue when IED is enabled

BZ: 32464

Video kernel driver need query DRM_CNTL_STATE register to know whether IED is enabled. Then return the state to user space driver.
When widevine is running, IED will be enabled and video surface will be encrypted. So CPU will only get scambled image.
For that case, need return error for vaDeriveImage and vaGetImage.

Change-Id: I9da4dfa88af241fb0729695b4e9e8266e8583bb0
Reviewed-on: http://android.intel.com:8080/48098
Reviewed-by: Jiang, Fei <fei.jiang@intel.com>
Reviewed-by: Sun, Mingruo <mingruo.sun@intel.com>
Reviewed-by: Qiu, Junhai <junhai.qiu@intel.com>
Reviewed-by: Ding, Haitao <haitao.ding@intel.com>
Tested-by: Ding, Haitao <haitao.ding@intel.com>
Reviewed-by: buildbot <buildbot@intel.com>
Tested-by: buildbot <buildbot@intel.com>