Patch merged into coreboot/master: arm64: Define stage_entry as weak symbol

the following patch was just integrated into master:
commit 6e1dc0cd602cea4d2b401970b032dadf2a082346
Author: Furquan Shaikh 
Date:   Fri Jul 10 15:25:26 2015 -0700

arm64: Define stage_entry as weak symbol

This allows SoCs/CPUs to have custom stage_entry in order to apply any
    fixups that need to run before standard cpu reset procedure.

BUG=chrome-os-partner:41877
    BRANCH=None
    TEST=Compiles successfully

Change-Id: Iaae7636349140664b19e81b0082017b63b13f45b
    Signed-off-by: Patrick Georgi 
    Original-Commit-Id: 498d04b0e9a3394943f03cad603c30ae8b3805d4
    Original-Change-Id: I9a005502d4cfcb76017dcae3a655efc0c8814a93
    Original-Signed-off-by: Furquan Shaikh 
    Original-Reviewed-on: https://chromium-review.googlesource.com/284867
    Original-Trybot-Ready: Furquan Shaikh 
    Original-Tested-by: Furquan Shaikh 
    Original-Reviewed-by: Aaron Durbin 
    Original-Commit-Queue: Furquan Shaikh 
    Reviewed-on: http://review.coreboot.org/10897
    Tested-by: build bot (Jenkins)
    Reviewed-by: Stefan Reinauer

See http://review.coreboot.org/10897 for details.

-gerrit