opencellular/rotundu: Add mainboard support

Adds Open Cellular rotundu mainboard supports.

Working:
  - 2x Ethernet support
  - MSATA support
  - CPU init
  - Memory init
  - USB support
  - EMMC but disabled

Not working:
  - TPM support

Create directory structure and Kconfig files for OpenCellular
Rotundu and copy sources from intel/minnowmax.

Change-Id: I391d4bdd485f4bf5396c764fe3f11d98369593e4
Signed-off-by: Hong Gan <hgan@fb.com>
Signed-off-by: David Hendricks <dhendricks@fb.com>
Reviewed-on: https://review.coreboot.org/22894
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Patrick Rudolph <siro@das-labor.org>
21 files changed