Makefile: Turn x86-arch comments into `if`

Actually check what the comments suggest. Supposed to fix non-x86 on
NetBSD and OpenBSD.

Change-Id: I440919c12e54ca4371e21bc8d1b5ab64692fb4b8
Signed-off-by: Nico Huber <nico.h@gmx.de>
Original-Reviewed-on: https://review.coreboot.org/c/flashrom/+/52486
Original-Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-on: https://review.coreboot.org/c/flashrom-stable/+/70928
Reviewed-by: Nico Huber <nico.h@gmx.de>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
1 file changed