util/superiotool: Check for libpci before builing

Check is adapted from inteltool's Makefile.

Change-Id: Ife01ef20d9284cb0a68719757856f9a66a4de452
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/19074
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
1 file changed