usb: uvc: make uvc_format_desc table const

usb: uvc: make uvc_format_desc table const

Since the uvc_fmts array can not be modified we declare it const and
change every user of the uvc_format_by_guid function aswell.

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Daniel Scally <dan.scally@ideasonboard.com>
Tested-by: Daniel Scally <dan.scally@ideasonboard.com>
Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
Link: https://lore.kernel.org/r/20230126231456.3402323-5-m.grzeschik@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>