USB: serial: ftdi_sio: Add Infineon Triboard

This adds support for Infineon TriBoard TC1798 [1]. Only interface 1
is used as serial line (see [2], Figure 8-6).

[1] http://www.infineon.com/cms/de/product/microcontroller/development-tools-software-and-kits/tricore-tm-development-tools-software-and-kits/starterkits-and-evaluation-boards/starter-kit-tc1798/channel.html?channel=db3a304333b8a7ca0133cfa3d73e4268
[2] http://www.infineon.com/dgdl/TriBoardManual-TC1798-V10.pdf?folderId=db3a304412b407950112b409ae7c0343&fileId=db3a304333b8a7ca0133cfae99fe426a



Signed-off-by: Michal Sojka <sojkam1@fel.cvut.cz>
Cc: Johan Hovold <johan@kernel.org>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>