arm64: Add support for transition library

Transition library provides the following functionalities:
1) Setup the environment for switching to any particular EL and jump to the
loaded program at that EL. In short "Execute program X at exception level Y
using the state Z"
2) Provides routines for exception entry and exception exit that can be used by
any program to implement exception handling. The only routine required by the
program would be exc_dispatch which handles the exception in its own required
way and returns by making a call to exc_exit. On exc_exit, the transition
library unwinds the whole stack by popping out the saved state of xregs

BUG=chrome-os-partner:30785
BRANCH=None
TEST=Compiles successfully and exceptions are tested for ramstage on ryu

Change-Id: I8116556109665e61a53e4b3987d649e3cfed64a1
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: 8ab888e8cae0c5f1e79b0e16ca292869f16f1cca
Original-Change-Id: I90f664ac657258724dc0c79bd9f6ceef70064f90
Original-Signed-off-by: Furquan Shaikh <furquan@google.com>
Original-Reviewed-on: https://chromium-review.googlesource.com/216375
Original-Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Original-Tested-by: Furquan Shaikh <furquan@chromium.org>
Original-Commit-Queue: Furquan Shaikh <furquan@chromium.org>
Reviewed-on: http://review.coreboot.org/9070
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>

0 files changed, 0 insertions, 0 deletions