toolchain: Use xcompile proposed CFLAGS for Ada

We don't output special ADAFLAGS in xcompile but its CFLAGS are
compatible with and necessary for Ada too. So use the latter and
make sure we use them for libgnat too.

Fixes i386 builds with x86_64 toolchain.

TEST=Gave libgfxinit a shot on lenovo/t420.

Change-Id: I0d13f182acfaa9bd1b608edd8a508c4ceedef3b3
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.coreboot.org/21363
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>

0 files changed, 0 insertions, 0 deletions