refactor(coreos-image.bbclass): use openssh instead of dropbear

BREAKING CHANGE: using the ssh-server IMAGE_FEATURES now install openssh
instead of dropbear

documentation/ref-manual/features.rst

@@ -36,7 +36,7 @@ these features is as follows:
 -  *hwcodecs:* Installs hardware acceleration codecs.
 -  *tools-debug:* Installs debugging tools such as ``strace`` and ``gdb``.
 -  *tools-profile:* Installs profiling tools such as ``valgrind`` and ``perf``.
--  *ssh-server:* Installs the Dropbear minimal SSH server.
+-  *ssh-server:* Installs the OpenSSH SSH server.
 -  *podman:*: Installs the Podman container runtime
 -  *networkmanager:* Installs the NetworkManager daemon and command line client
 -  *cockpit:* Installs the cockpit web interface

layers/meta-belden-coreos/classes/coreos-image.bbclass

@@ -46,8 +46,8 @@ MACHINE_HWCODECS ??= ""
 #
 # ssh-server: provide a ssh server, on core-image, two ssh server are supported
 #             and the features ssh-server-dropbear and ssh-server-openssh are 
-#             available. For CoreOS, we only support dropbear
-FEATURE_PACKAGES_ssh-server = "packagegroup-core-ssh-dropbear"
+#             available. For CoreOS, we only support openssh
+FEATURE_PACKAGES_ssh-server = "packagegroup-core-ssh-openssh"
 
 # The ptest distro feature want to install openssh-ptest by default, that conflict with dropbear
 # Do not install openssh complementary packages if either packagegroup-core-ssh-dropbear or dropbear