The xgcc toolchain may be moved by the user and passed in on the commandline. Updates the Makefile and the xcompile script.
Change-Id: I05797b2cabce39bdd7868c2515f30d34043fc8cc
Signed-off-by: Marc Jones <marcj303@gmail.com>
Reviewed-on: http://review.coreboot.org/318
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <patrick@georgi-clan.de>