[media] v4l: Convert drivers to use monotonic timestamps

Convert drivers using wall clock time (CLOCK_REALTIME) to timestamp from the
monotonic timer (CLOCK_MONOTONIC).

Signed-off-by: Sakari Ailus <sakari.ailus@iki.fi>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/usb/sn9c102/sn9c102_core.c

@@ -773,7 +773,8 @@ end_of_frame:
 				       img);
 
 				if ((*f)->buf.bytesused == 0)
-					do_gettimeofday(&(*f)->buf.timestamp);
+					v4l2_get_timestamp(
+						&(*f)->buf.timestamp);
 
 				(*f)->buf.bytesused += img;