contrib: speex: avoid automatically depending on ogg

ogg was still being pulled in as a dependency when cross-compiling, which
would break certain build configurations.

contrib/src/speex/rules.mak

@@ -27,7 +27,7 @@ speex: speex-$(SPEEX_VERSION).tar.gz .sum-speex
 	$(ZCAT) "$<" | (cd $@-git && tar xv --strip-components=1)
 	$(MOVE)
 
-SPEEX_CONF := --without-ogg
+SPEEX_CONF := --disable-binaries
 ifndef HAVE_FPU
 SPEEX_CONF += --enable-fixed-point
 ifeq ($(ARCH),arm)