usb: gadget: uvc: add trace of enqueued and completed requests

This patch is adding trace events for each request that is being
enqueued into the hw and will be completed. This way it is possible
to track the fill status of the gadget hardware and find potential
issues.

Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
Link: https://lore.kernel.org/r/20240403-uvc_request_length_by_interval-v7-8-e224bb1035f0@pengutronix.de


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>