patch: u3g + quirks: Add DTR/RTS support for QUALCOMM MSM6800 based modems

[Alexandr Rybalko]

Hi,

The attached patch (also at http://my.ddteam.net/files/usb.serial.diff) add support for DTR/RTS on QUALCOMM MSM6800
based modems (Known: AnyData ADU-500A, ADU-510A).

Please review and apply if the changes are okay.
Let me know if you have any comments.

-- 
Alexandr Rybalko <ray at dlink.ua> 
aka Alex RAY <ray at ddteam.net>