buildgcc: build with bfd and gold linker

Build with bfd and gold linker, but use bfd linker per default
and make sure that lto is enabled in both binutils and gcc

Change-Id: I0584396b4580674cfdca24fbed0d8eeb1ee38806
Signed-off-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Reviewed-on: http://review.coreboot.org/10496
Tested-by: build bot (Jenkins)
Reviewed-by: Edward O'Callaghan <edward.ocallaghan@koparo.com>

util/crossgcc/buildgcc

@@ -382,7 +382,7 @@ build_BINUTILS() {
 	# Now build binutils
 	CC="$CC" ../binutils-${BINUTILS_VERSION}/configure --prefix=$TARGETDIR \
 		--target=${TARGETARCH} --disable-werror --disable-nls \
-		$USE_GOLD CFLAGS="$HOSTCFLAGS" || touch .failed
+		--enable-lto --enable-gold --enable-plugins CFLAGS="$HOSTCFLAGS" || touch .failed
 	$MAKE $JOBS || touch .failed
 	$MAKE install DESTDIR=$DESTDIR || touch .failed
 }
@@ -398,9 +398,10 @@ build_GCC() {
 		CFLAGS_FOR_BUILD="$HOSTCFLAGS" ../gcc-${GCC_VERSION}/configure \
 		--prefix=$TARGETDIR --libexecdir=$TARGETDIR/lib \
 		--target=${TARGETARCH} --disable-werror --disable-shared \
+		--enable-lto --enable-plugins --enable-gold --enable-ld=default \
 		--disable-libssp --disable-bootstrap --disable-nls \
 		--disable-libquadmath --without-headers \
-		$GCC_OPTIONS --enable-languages="c" $USE_GOLD \
+		${GCC_OPTIONS} --enable-languages="c" \
 		--with-gmp=$DESTDIR$TARGETDIR --with-mpfr=$DESTDIR$TARGETDIR \
 		--with-mpc=$DESTDIR$TARGETDIR --with-libelf=$DESTDIR$TARGETDIR \
 		--with-pkgversion="coreboot toolchain v$CROSSGCC_VERSION $CROSSGCC_DATE" \
@@ -596,11 +597,6 @@ if [ "$USECCACHE" = 1 ]; then
 	CC="ccache $CC"
 fi
 
-# coreboot does not like the GOLD linker
-# USE_GOLD="--enable-gold"
-USE_GOLD=""
-GCC_OPTIONS="--enable-lto"
-
 # Prepare target directory for building GCC
 # (dependencies must be in the PATH)
 mkdir -p $DESTDIR$TARGETDIR/bin