crossgcc: Fix building with clang++ in the presence of gcc

Some environments (<grumble>cros_sdk</grumble>) provide gcc as $CC and
clang++ as $CXX. The latter needs the higher bracket-depth while the
former has no idea what it means, so tell CC and CXX individually.

Change-Id: I72b75fb9bb5df3a9b1561ee8821ec43ada29b24f
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Reviewed-on: https://review.coreboot.org/20365
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
1 file changed