Revert "usb: gadget: uvc: stop pump thread on video disable"

This reverts commit 3a63f86c

.

Based on review comments, it was applied too soon and needs more work.

Reported-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: https://lore.kernel.org/r/20231005081716.GA13853@pendragon.ideasonboard.com
Cc: Michael Grzeschik <m.grzeschik@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>