Makefile: Rework NI-845x detection

Since the NI-845x is a Windows only proprietary library, disable it by
default. Use `HAS_LIB_NI845X=yes` to enable it. The default search path
is `${PROGRAMFILES}\National Instruments\NI-845x\MS Visual C` and can be
overwritten by `CONFIG_NI845X_LIBRARY_PATH`. Use
`CONFIG_LIB_NI845X_CFLAGS` and `CONFIG_LIB_NI845X_LDFLAGS` for setting
the cflags and ld flags manually.

Change-Id: I918c3605a5ac168708a6a10fd92ee2a1aae9729b
Signed-off-by: Thomas Heijligen <thomas.heijligen@secunet.com>
Reviewed-on: https://review.coreboot.org/c/flashrom/+/59047
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Nico Huber <nico.h@gmx.de>

0 files changed, 0 insertions, 0 deletions