package/cups: Add udev rules to assign usb printers group to lp

package/cups: Add udev rules to assign usb printers group to lp

This patch is based on patch from the rockchip tree:

commit c8a337593660f27379c30248a11bf08dc8712113
Author: Jeffy Chen <jeffy.chen@rock-chips.com>
Date:   Tue Nov 13 18:59:43 2018 +0800

    package: cups: Add udev rules to assign usb printers' group to lp

    Change-Id: Ieae17deaa7d3623e1f0e1cc826871f1719d98d88
    Signed-off-by: Jeffy Chen <jeffy.chen@rock-chips.com>
but removes a hardcoded device usb vendor/id and keps only the usb
printer class.

Signed-off-by: Angelo Compagnucci <angelo@amarulasolutions.com>
Signed-off-by: Michael Trimarchi <michael@amarulasolutions.com>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>