[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>
diff --git a/drivers/media/usb/pwc/pwc-if.c b/drivers/media/usb/pwc/pwc-if.c
index 5210239..21c1523 100644
--- a/drivers/media/usb/pwc/pwc-if.c
+++ b/drivers/media/usb/pwc/pwc-if.c
@@ -316,7 +316,8 @@
 			struct pwc_frame_buf *fbuf = pdev->fill_buf;
 
 			if (pdev->vsync == 1) {
-				do_gettimeofday(&fbuf->vb.v4l2_buf.timestamp);
+				v4l2_get_timestamp(
+					&fbuf->vb.v4l2_buf.timestamp);
 				pdev->vsync = 2;
 			}