haswell: support for CONFIG_RELOCATABLE_RAMSTAGE

Now that CONFIG_RELOCTABLE_RAMSTAGE is available support it on
Haswell-based systems. This patch is comprised of the following changes:

1. Ensure that memory is not preserved when a relocatable ramstage is
   enabled. There is no need.
2. Pick the proper stack to use after cache-as-ram is torn down. When
   the ramstage is relocatable, finding a stack to use before vectoring
   into ramstage is impossible since the ramstage is a black box with an
   unknown layout.

Change-Id: I2a07a497f52375569bae9c994432a8e7e7a40224
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: http://review.coreboot.org/2793
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
1 file changed