Patch merged into coreboot/master: 5f7e4f0 make: support absolute and relative obj= specifications

the following patch was just integrated into master:
commit 5f7e4f019e258a49fff78e90509d1fda280fc147
Author: Vadim Bendebury 
Date:   Wed May 6 21:00:10 2015 -0700

make: support absolute and relative obj= specifications

There has been a problem with out of tree build directories specified
    using relative paths, as in

$ make obj=../build/peppy

while specifying full path to obj works fine. This patch fixes the
    problem, making sure that make's path manipulation string substitute
    command is applied to both source and build roots.

To test this ran the following script

echo > /tmp/build.log
    for build_root in ./ ../ ''; do
      build_dirs="${build_root}build/peppy"
      if [ -n "${build_root}" ]; then
        build_dirs+=" $(realpath ${build_root})/build/peppy"
      fi
      for build_dir in ${build_dirs}; do
        rm -rf $build_dir .config* build* ../build*
        make obj=${build_dir} menuconfig # configure for google peppy board
        echo "building in ${build_dir}" >> /tmp/build.log
        if ! make obj=${build_dir}; then
          exit
        fi
      done
    done

and then checked the generated file:

$ cat /tmp/build.log

building in ./build/peppy
    building in /home/vbendeb/old_projects/coreboot/source_code/build/peppy
    building in ../build/peppy
    building in /home/vbendeb/old_projects/coreboot/build/peppy
    building in build/peppy

Change-Id: If46b046108e906796fe84716e93bf341b3785f14
    Signed-off-by: Vadim Bendebury 
    Reviewed-on: http://review.coreboot.org/10127
    Tested-by: build bot (Jenkins)
    Reviewed-by: Patrick Georgi

See http://review.coreboot.org/10127 for details.

-gerrit