usb: gadget: uvc: implement dwPresentationTime and scrSourceClock

usb: gadget: uvc: implement dwPresentationTime and scrSourceClock

This patch adds the fields UVC_STREAM_PTS and UVC_STREAM_SCR to the uvc
header, in case this data is available. It also enables the copy of the
timestamp to the vb2_v4l2_buffer by setting V4L2_BUF_FLAG_TIMESTAMP_COPY
in the queue.timestamp_flags.

Signed-off-by: Michael Olbrich <m.olbrich@pengutronix.de>
Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
Link: https://lore.kernel.org/r/20211022093223.26493-2-m.grzeschik@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>