crossgcc: Allow the non-gnu tar and patch work on XxxBSD

For BSD, patch and tar are not default GNU. Add a work around
to let the non-gun patch and tar work.

Change-Id: I0a9d0bb0e535aa5e0dde146db330c3c8d7b4d8cb
Signed-off-by: Zheng Bao <zheng.bao@amd.com>
Signed-off-by: Zheng Bao <fishbaozi@gmail.com>
Reviewed-on: http://review.coreboot.org/1502
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
1 file changed