Makefile: use pkg-config --libs --static for LDFLAGS

The --static flag of pkg-config returns also the LDFLAGS which are
required to link the library static. Use this flag to successfully
link against static libraries when the shared variant is not available.
This is the case in OpenBSD with libpci.

Change-Id: I6029a096c1ceca625789d18c88119d912d79bc0e
Signed-off-by: Thomas Heijligen <thomas.heijligen@secunet.com>
Original-Reviewed-on: https://review.coreboot.org/c/flashrom/+/61524
Original-Reviewed-by: Nico Huber <nico.h@gmx.de>
Original-Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-on: https://review.coreboot.org/c/flashrom-stable/+/72292
Reviewed-by: Nico Huber <nico.h@gmx.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
2 files changed