haswell: unify romstage logic

This commit pulls in all the common logic for romstage into
the Haswell cpu directory. The bits specific to the mainboard
still reside under their respective directories. The calling
sequence bounces from the cpu directory to mainboard then back
to the cpu directory. The reasoning is that Haswell systems use
cache-as-ram for backing memory in romstage. The stack is used to
allocate structures. However, now changes can be made to the
romstage for Haswell and apply to all boards.

Change-Id: I2bf08013c46a99235ffe4bde88a935c3378eb341
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: http://review.coreboot.org/2754
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
5 files changed