[PATCH 13/20] davinci_vpfe: Add video_device and vb2_queue locks

Currently, this driver does not serialize its video4linux ioctls, which is a bug, as race conditions might appear. In addition, video_device and vb2_queue locks are now both mandatory. Add them, and implement wait_prepare and wait_finish. To stay on the safe side, this commit uses a single mutex

[PATCH 13/20] davinci_vpfe: Add video_device and vb2_queue locks

Currently, this driver does not serialize its video4linux ioctls, which is a bug, as race conditions might appear. In addition, video_device and vb2_queue locks are now both mandatory. Add them, and implement wait_prepare and wait_finish. To stay on the safe side, this commit uses a single mutex