buildgcc: Ask the user to install gnat if it's missing

Change-Id: Ib840eac29fc8cedfaef4847fd9700bd4a70300ba
Signed-off-by: Nico Huber <nico.huber@secunet.com>
Reviewed-on: https://review.coreboot.org/16677
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
1 file changed