VX900: Add support for early romstage

Add support for VX900 early initialization up until, but not including
raminit. Add the basic infrastructure, add a romstrap table, and
functionality to configure the CPU bus and SMBus.

This code is necessary and sufficient to prepare us for raminit.

Change-Id: Icc9c41e4927b589f17416836f87a6a5843b24aa7
Signed-off-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
Reviewed-on: http://review.coreboot.org/3372
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
12 files changed