staging: dt3155v4l: make q_ops static

Since q_ops is only referenced in dt3155v4l.c, mark it as static.

This removes the following sparse warning:
drivers/staging/media/dt3155v4l//dt3155v4l.c:302:22: warning: symbol 'q_ops' was not declared. Should it be static?
Signed-off-by: Kristina Martšenko <kristina.martsenko@gmail.com>
Signed-off-by: Peter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>

drivers/staging/media/dt3155v4l/dt3155v4l.c

@@ -299,7 +299,7 @@ dt3155_buf_queue(struct vb2_buffer *vb)
  *	end driver-specific callbacks
  */
 
-const struct vb2_ops q_ops = {
+static const struct vb2_ops q_ops = {
 	.queue_setup = dt3155_queue_setup,
 	.wait_prepare = dt3155_wait_prepare,
 	.wait_finish = dt3155_wait_finish,