Move to new override syntax

Signed-off-by: Andreas Müller <schnitzeltony@gmail.com>

classes/cmake_sysroot.bbclass

@@ -4,14 +4,14 @@
 CMAKEINSTALLED = "${WORKDIR}/staged_cmake_files"
 
 # 1. remove tmp file from last build
-python do_populate_sysroot_prepend() {
+python do_populate_sysroot:prepend() {
     tmpfile = d.getVar('CMAKEINSTALLED')
     if os.path.isfile(tmpfile):
         os.remove(tmpfile)
 }
 
 # 2. keep cmake files staged to sysroot
-sysroot_stage_dir_append() {
+sysroot_stage_dir:append() {
     # avoid doubles causing double replacement
     for file in `find $dest -name '*.cmake'`; do
         if ! grep -q "$file" ${CMAKEINSTALLED} ; then