util/amdfwtool,post: add missing distclean target

Without this target some spurious errors occurred when running make
distclean at the top level of coreboot.

Change-Id: I3d3061b386fc5b4a043cfc7ff8fd3c0da33c0e83
Signed-off-by: Felix Held <felix-coreboot@felixheld.de>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/49227
Reviewed-by: Raul Rangel <rrangel@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

0 files changed, 0 insertions, 0 deletions