gcc: disable libgomp when thread support is disabled

libgomp needs thread support on the target to build properly.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>

toolchain/gcc/gcc-uclibc-4.x.mk

@@ -139,7 +139,7 @@ GCC_TLS:=--disable-tls
 endif
 
 ifeq ($(BR2_PTHREADS_NONE),y)
-THREADS:=--disable-threads
+THREADS:=--disable-threads --disable-libgomp
 else
 THREADS:=--enable-threads
 endif