cpu/microcode: Fix config CPU_MICROCODE_CBFS_EXTERNAL_BINS

Make the variable override for CPU_MICROCODE_CBFS_EXTERNAL_BINS local to
the target. Otherwise, `cpu_microcode_bin +=` lines that are evaluated
after `src/cpu/Makefile.inc` still append to it.

Change-Id: If81f307afc325ff3c1e987e9483ed5e45fdc403e
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/39031
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Matt DeVillier <matt.devillier@gmail.com>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>

0 files changed, 0 insertions, 0 deletions