Patch merged into coreboot/master: arch/arm64: Avoid race condition when building bl31

the following patch was just integrated into master:
commit 2268b3b750cd009992de4173f5d2fa8640f5a8de
Author: Patrick Georgi 
Date:   Mon Jun 29 22:13:53 2015 +0200

arch/arm64: Avoid race condition when building bl31

The arm-trusted-firmware build system may not create the final bl31.elf file
    atomically, confusing our make to try to use it before it's ready.
    Hence insert a (hopefully, but not guaranteed to be atomic) file move.

Change-Id: Iffc80467e0f4bbc96fc62414d4abfaa7b42634f4
    Signed-off-by: Patrick Georgi 
    Reviewed-on: http://review.coreboot.org/10700
    Reviewed-by: Stefan Reinauer 
    Tested-by: build bot (Jenkins)

See http://review.coreboot.org/10700 for details.

-gerrit