Patch merged into coreboot/master: db27306 build system: extend src-to-obj for non-.c/.S files

the following patch was just integrated into master:
commit db273065f67ef432937399a324364822539ca559
Author: Patrick Georgi 
Date:   Fri Mar 27 17:03:28 2015 +0100

build system: extend src-to-obj for non-.c/.S files

It also creates file names in the build directory and with
    the stage sliced in, but keeps the extension for anything
    not .c or .S.

Also some handling for non-.c/.S files was adapted to match.

This is inspired by the commit listed below, but rewritten to match
    upstream, and split in smaller pieces to keep intent clear.

Change-Id: If8f89a7daffcf51f430b64c3293d2a817ae5120f
    Signed-off-by: Patrick Georgi 
    Based-On-Change-Id: I50af7dacf616e0f8ff4c43f4acc679089ad7022b
    Based-On-Signed-off-by: Julius Werner 
    Based-On-Reviewed-on: https://chromium-review.googlesource.com/219170
    Reviewed-on: http://review.coreboot.org/9175
    Reviewed-by: Aaron Durbin 
    Tested-by: build bot (Jenkins)

See http://review.coreboot.org/9175 for details.

-gerrit