Minimal Android.mk sufficient to build host tools to compile
futility vbutil_keyblock and vbutil_kernel to sign kernel images.
BUG=none
TEST='mm' from within Android tree compiles
BRANCH=none
Change-Id: Ie46be27cd14a5ca73a23eb52238eb9fd326ccaf4
Signed-off-by: David Riley <davidriley@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/247820
