crossgcc: properly test for flex
This is no GNU tool, so testing for "GNU" in the version string
is bound to fail.
We now accept everything that returns success on "flex --version"
and then hope for the best.
I tested both cases
Change-Id: If325f613fde1648847b998b7e8e5782d0f22b484
Signed-off-by: Patrick Georgi <patrick.georgi@secunet.com>
Reviewed-on: http://review.coreboot.org/1884
Tested-by: build bot (Jenkins)
Reviewed-by: Zheng Bao <zheng.bao@amd.com>
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>