USB: Add device id for Option GTM380 to option driver

Option GTM380 in Modem mode uses Product ID 0x7201. This has been tested and works
on production systems for over 6 months.

Signed-off-by: Achilleas Kotsis <akots@exponent.gr>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>