arch/mips: Add base MIPS architecture support

Add the build infrastructure and basic architectural support required
to build for targets using the MIPS architecture. This is sufficient
to run on a simulator, but will require the addition of some cache
maintenance and timer setup in order to run on real hardware.

BUG=chrome-os-partner:31438, chromium:409082
TEST=none yet

Change-Id: I027902d8408e419b626d0aab7768bc564bd49047
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: fcc0d934d7223922c878b1f87021cb5c2d7e6f21
Original-Change-Id: If4f99554463bd3760fc142477440326fd16c67cc
Original-Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Original-Signed-off-by: Vadim Bendebury <vbendeb@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/207972
Original-Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: http://review.coreboot.org/8760
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
29 files changed