USB: Add vendor/product id of ZTE MF628 to option

This adds the vendor and product id (19d2:0015) of the ZTE MF628 HSDPA
modem to the option driver. It still needs a mode switch command issued
beforehand, this is currently handled by a userspace tool.

Signed-off-by: Oliver Martin <oliver.martin@student.tuwien.ac.at>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>