Convert to new override syntax (#357)

* Convert to new override syntax

This is the result of automated script (0.9.0) conversion:

oe-core/scripts/contrib/convert-overrides.py .

converting the metadata to use ":" as the override character instead of "_".

Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>

* Manually fix the conversion

Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>

* layer.conf: Update layer compatibility with only dunfell and newer.

Add honister to mark the layers as compatible with honister now that it uses
the new override syntax.

Drop zeus and older which are missing a support for newer override syntax which
was backported only to 1.46 branch (used by dunfell) and newer, e.g.:
https://git.openembedded.org/bitbake/commit/?h=1.46&id=c5418eae56cc50dbae7951c055434a0c456c53a4

Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>

* CI: use YOCTO_BRANCH instead of yocto-${YOCTO_VERSION} for poky checkout

* using latest revision in branch is often better than sticking to
  some point releases

Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>

* CI: switch to hardknott branch

* gatesgarth is already EOL, better to use something supported

Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>

recipes-devtools/cargo/cargo.inc

@@ -25,7 +25,7 @@ do_cargo_setup_snapshot () {
 addtask cargo_setup_snapshot after do_unpack before do_configure
 do_cargo_setup_snapshot[dirs] += "${WORKDIR}/${CARGO_SNAPSHOT}"
 
-do_compile_prepend () {
+do_compile:prepend () {
 	export RUSTC_BOOTSTRAP="1"
 }
 
@@ -47,5 +47,5 @@ BBCLASSEXTEND = "native nativesdk"
 
 # When building cargo-native we don't have cargo-native to use and depend on,
 # so we must use the locally set up snapshot to bootstrap the build.
-BASEDEPENDS_remove_class-native = "cargo-native"
-CARGO_class-native = "${WORKDIR}/${CARGO_SNAPSHOT}/bin/cargo"
+BASEDEPENDS:remove:class-native = "cargo-native"
+CARGO:class-native = "${WORKDIR}/${CARGO_SNAPSHOT}/bin/cargo"