vboot: allow non-relocatable ramstage loading

vboot: allow non-relocatable ramstage loading

The vboot implementation previously assumed that ramstage would
be a relocatable module. Allow for ramstage not being a relocatable
module.

BUG=chrome-os-partner:27094
BRANCH=None
TEST=Built nyan with vboot.

Original-Change-Id: Id3544533740d77e2db6be3960bef0c129173bacc
Original-Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/190923
Original-Reviewed-by: Gabe Black <gabeblack@chromium.org>
(cherry picked from commit 756ee3a6987097c65588c8784ee9653fd6e735e4)
Signed-off-by: Marc Jones <marc.jones@se-eng.com>
Change-Id: I813b07e1bec75640ad4066aca749ba8dccec31d4
Reviewed-on: http://review.coreboot.org/7220
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>