[coreboot-gerrit] Patch merged into coreboot/master: crossgcc: Update makefile builds

the following patch was just integrated into master:
commit 8fe681872b38c23a2a9172199d1e9c0edae12937
Author: Martin Roth 
Date:   Tue Oct 27 15:03:46 2015 -0600

crossgcc: Update makefile builds

- Only build IASL once for the 'all' targets instead of once for each.
    - Change the control of what gets built from different targets to
    variables on the build line.
    - Clean up and correct the list of phony targets
    - Don't keep the temporary files around while building all.  This
    takes up a lot of space.  If it's desired behavior, add
    BUILDGCC_OPTIONS=-t on the make command line.
    - Add comments about CPU= and BUILDGCC_OPTIONS= variables
    - Add KEEP_SOURCES option

Change-Id: I7752974e249f25717b42be25a841c69af84d5c69
    Signed-off-by: Martin Roth 
    Reviewed-on: http://review.coreboot.org/12300
    Tested-by: build bot (Jenkins)
    Reviewed-by: Patrick Georgi

See http://review.coreboot.org/12300 for details.

-gerrit