gigabyte/ga-b75m-d3h: Add new Intel mainboard

This is based on LENOVO X230 port. Board boots to linux via SATA.

Remaining Issues:

1. Native raminit sometimes fails with "timC write discovery failed"
   even without changing the ram configuration.
   I suggest altering the native raminit code so that it reboots
   if that message appears to give a chance for the boot process to recover.

2. VGA does not work.
   Native graphics initialization only supports LVDS and the
   VGA Option ROM still hangs when run in SeaBIOS

3. USB does not work.
   SeaBIOS/GRUB2 do not detect devices connected to USB ports

4. Sound needs corrected codec verb settings

Change-Id: Ib465a4824ef1a71ab6aa17bd40fc281215c6d44f
Signed-off-by: Damien Zammit <damien@zamaudio.com>
Reviewed-on: http://review.coreboot.org/7020
Tested-by: build bot (Jenkins)
Reviewed-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>