buildgcc: enable interwork/multilib for binutils

Otherwise, on OS X, some architectures will fail
to build libgcc (verified for ARM toolchain).

Change-Id: I8b58e0582596ad39cad92e9d478158c46a96a26e
Signed-off-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Reviewed-on: https://review.coreboot.org/14256
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
diff --git a/util/crossgcc/buildgcc b/util/crossgcc/buildgcc
index 96e4c19..4641ae9 100755
--- a/util/crossgcc/buildgcc
+++ b/util/crossgcc/buildgcc
@@ -446,6 +446,7 @@
 	CC="$CC" ../binutils-${BINUTILS_VERSION}/configure --prefix=$TARGETDIR \
 		--target=${TARGETARCH} --enable-targets=${TARGETARCH}${ADDITIONALTARGET} \
 		--disable-werror --disable-nls --enable-lto --enable-gold \
+		--enable-interwork --enable-multilib \
 		--enable-plugins --enable-multilibs CFLAGS="$HOSTCFLAGS" || touch .failed
 	$MAKE $JOBS || touch .failed
 	$MAKE install DESTDIR=$DESTDIR || touch .failed