arm64: tegra132: tegra210: Remove old arm64/stage_entry.S

This patch removes the old arm64/stage_entry.S code that was too
specific to the Tegra SoC boot flow, and replaces it with code that
hides the peculiarities of switching to a different CPU/arch in ramstage
in the Tegra SoC directories.

BRANCH=None
BUG=None
TEST=Built Ryu and Smaug. !!!UNTESTED!!!

Change-Id: Ib3a0448b30ac9c7132581464573efd5e86e03698
Signed-off-by: Julius Werner <jwerner@chromium.org>
Reviewed-on: http://review.coreboot.org/12078
Tested-by: build bot (Jenkins)
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
33 files changed