[media] media: s5p-mfc: use vb2_ops_wait_prepare/finish helper

This patch drops driver specific wait_prepare() and
wait_finish() callbacks from vb2_ops and instead uses
the the helpers vb2_ops_wait_prepare/finish() provided
by the vb2 core, the lock member of the queue needs
to be initalized to a mutex so that vb2 helpers
vb2_ops_wait_prepare/finish() can make use of it.

Signed-off-by: Lad, Prabhakar <prabhakar.csengg@gmail.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Kamil Debski <k.debski@samsung.com>
Cc: Jeongtae Park <jtp.park@samsung.com>
Signed-off-by: Kamil Debski <k.debski@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
diff --git a/drivers/media/platform/s5p-mfc/s5p_mfc.c b/drivers/media/platform/s5p-mfc/s5p_mfc.c
index fbfdf03..8e44a59 100644
--- a/drivers/media/platform/s5p-mfc/s5p_mfc.c
+++ b/drivers/media/platform/s5p-mfc/s5p_mfc.c
@@ -810,6 +810,7 @@
 	q = &ctx->vq_dst;
 	q->type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
 	q->drv_priv = &ctx->fh;
+	q->lock = &dev->mfc_mutex;
 	if (vdev == dev->vfd_dec) {
 		q->io_modes = VB2_MMAP;
 		q->ops = get_dec_queue_ops();