chore(linux-yocto): remove support for signing the kernel

CoreOS sign the unified kernel image but had the option to sign
the kernel image as well. This option was disabled by default
and as far as I know was never used and is not really needed.

layers/meta-belden-coreos/recipes-kernel/linux/linux-yocto-coreos.inc

@@ -4,26 +4,5 @@ FILESEXTRAPATHS:prepend := "${THISDIR}/files:"
 # ==============================================================================
 SRC_URI += "file://secure-storage.cfg"
 
-# EFI Support
+# Ensure the Kernel EFI STUB is enabled
-# ==============================================================================
-inherit coreos-efi-sbsign
-require conf/image-uefi.conf
-
-# Ensure EFI STUB is enabled
 KERNEL_FEATURES += "cfg/efi.scc cfg/efi-ext.scc"
-
-# By default we use a Unified Kernel Image that contain the kernel, the
-# kernel command line and some device tree, so we don't need to sign the output
-# of the kernel recipes
-COREOS_KERNEL_EFI_SIGNED ??= "0"
-
-# Extend the kernel_do_deploy function from kernel.bbclass to sign the kernel
-kernel_do_deploy:append() {
-    if [ "${COREOS_KERNEL_EFI_SIGNED}" == "1" ]; then
-      deployDir="${DEPLOYDIR}"
-      for imageType in ${KERNEL_IMAGETYPES} ; do
-        baseName="$imageType-${KERNEL_IMAGE_NAME}"
-        coreos_efi_secureboot_sign_app "$deployDir/$baseName${KERNEL_IMAGE_BIN_EXT}"
-      done
-    fi
-}

layers/meta-belden-marvell-bsp/recipes-kernel/linux/linux-netmodule_git-5.15-solidrun.bb

@@ -32,4 +32,7 @@ do_configure:append(){
     fi
 }
 
+# linux-yocto-coreos.inc provide some kernel config fragment that we can apply
+# Note that KERNEL_FEATURES are not applied as this recipes doesn't ihnerit
+# the linux-yocto class.
 require recipes-kernel/linux/linux-yocto-coreos.inc

layers/meta-netmodule-coreos-bsp/recipes-kernel/linux/linux-ti-coreos_git-5.10.bb

@@ -23,4 +23,7 @@ do_configure:append(){
     fi
 }
 
+# linux-yocto-coreos.inc provide some kernel config fragment that we can apply
+# Note that KERNEL_FEATURES are not applied as this recipes doesn't ihnerit
+# the linux-yocto class.
 require recipes-kernel/linux/linux-yocto-coreos.inc