util: Add Nix shell file

Add a Nix shell file which is able to compile flashrom.

flashrom-stable: Drop cmocka.

Change-Id: I9757b952f4b034e98c2b4b70fbede52d8efb9d50
Signed-off-by: Felix Singer <felix.singer@secunet.com>
Original-Reviewed-on: https://review.coreboot.org/c/flashrom/+/58012
Original-Reviewed-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.coreboot.org/c/flashrom-stable/+/73399
Reviewed-by: Nico Huber <nico.h@gmx.de>
Reviewed-by: Felix Singer <felixsinger@posteo.net>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
1 file changed