18 months ago 5bbf89fc260830f3f58b331d946a16b39ad1ca2d changed to loading
bzImages directly, and no longer manually ungzipping them, so we no longer
need libz.
Also, -m32 is useful for those on 64-bit platforms (and harmless on
32-bit).
Reported-by: Ron Minnich
Signed-off-by: Rusty Russell