siemens/mc_bdx1: Add new mainboard.

Add new mainboard for MC BDX1 board which is based on Intel Camelback
Mountain. This mainboard is an industry type board and has several
Ethernet interfaces among with two USB3.0 connectors. It uses 24V DC
power supply and has its own form factor which does not match any
standard.
This commit adds the new mainboard and prepares the Kconfig
environment so that this board can be selected and generated.
Although the generated image can boot into Linux and DOS,
not all functions are implemented yet.
Forthcoming commits will add more functionality.

Change-Id: I29011cfd3b0d13bcf163223f657e02f69978e39a
Signed-off-by: Werner Zeh <werner.zeh@siemens.com>
Reviewed-on: https://review.coreboot.org/14516
Tested-by: build bot (Jenkins)
Reviewed-by: York Yang <york.yang@intel.com>
15 files changed