ARM: Add an ARMv4 architecture version.

This is needed for the tegra124's bootblock and includes enough implementation
to support that use. No caching is supported, although there are function
prototypes and stub implementations to satisfy includes and linking.

BUG=chrome-os-partner:23009
TEST=Built and booted into the bootblock on nyan. Built for link, falco, pit
and snow.
BRANCH=None

Change-Id: Ib79dde8c30eda98b3e823cba2ff6115a610bb2e8
Signed-off-by: Gabe Black <gabeblack@google.com>
Reviewed-on: https://chromium-review.googlesource.com/171401
Reviewed-by: Gabe Black <gabeblack@chromium.org>
Tested-by: Gabe Black <gabeblack@chromium.org>
Commit-Queue: Gabe Black <gabeblack@chromium.org>
9 files changed