sox: Explicitly disable support for OpenMP

In case a toolchain happens to be built with OpenMP, sox's configure
script would be picking that, but we would not be depending on libgomp
and would fail creating the package.

Since internal OpenWrt/LEDE toolchains don't enable OpenMP by default,
let's just do that here as well.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>

sound/sox/Makefile

@@ -52,7 +52,8 @@ CONFIGURE_ARGS += \
 		--without-png \
 		--without-sndfile \
 		--with-lame \
-		--with-id3tag
+		--with-id3tag \
+		--disable-openmp
 
 define Build/InstallDev
 	$(INSTALL_DIR) $(1)/usr/include