Convert to new overrides syntax for honister

Signed-off-by: Christopher Larson <chris_larson@mentor.com>

core/recipes-devtools/binutils/binutils-cross_%.bbappend

@@ -1,4 +1,4 @@
-do_install_append_tcmode-external () {
+do_install:append:tcmode-external () {
     install -d ${D}${bindir}/gcc
     for i in ${D}${bindir}/${TARGET_PREFIX}*; do
         ln -s ../$(basename "$i") ${D}${bindir}/gcc/${i##*/${TARGET_PREFIX}}