USB: serial: ti_usb_3410_5052: Add support for the FRI2 serial console

commit 975dc33b82cb887d75a29b1e3835c8eb063a8e99 upstream.

The Kontron M2M development board, also known as the Fish River Island II,
has an optional daughter card providing access to the PCH_UART (EG20T) via
a ti_usb_3410_5052 uart to usb chip.

http://us.kontron.com/products/systems+and+platforms/m2m/m2m+smart+services+developer+kit.html

Signed-off-by: Darren Hart <dvhart@linux.intel.com>
CC: Al Borchers <alborchers@steinerpoint.com>
CC: Peter Berger <pberger@brimson.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>