distro/rhel9: support kernel options in edge images

Add kernel options to the image type for edge images (raw, ami, and
vsphere) and handle them in the edgeRawImage() function.
Move the 'modprobe.blacklist=vc4' option, which was used to be set in
the image function, to the image types instead.

pkg/distro/rhel8/edge.go

@@ -65,12 +65,13 @@ func edgeRawImgType() imageType {
 		filename:            "image.raw.xz",
 		compression:         "xz",
 		mimeType:            "application/xz",
+		image:               edgeRawImage,
 		packageSets:         nil,
 		defaultSize:         10 * common.GibiByte,
 		rpmOstree:           true,
 		bootable:            true,
 		bootISO:             false,
-		image:               edgeRawImage,
+		kernelOptions:       "modprobe.blacklist=vc4",
 		buildPipelines:      []string{"build"},
 		payloadPipelines:    []string{"ostree-deployment", "image", "xz"},
 		exports:             []string{"xz"},

pkg/distro/rhel9/edge.go

@@ -69,6 +69,7 @@ var (
 		defaultImageConfig: &distro.ImageConfig{
 			Locale: common.ToPtr("en_US.UTF-8"),
 		},
+		kernelOptions:       "modprobe.blacklist=vc4",
 		defaultSize:         10 * common.GibiByte,
 		rpmOstree:           true,
 		bootable:            true,
@@ -145,7 +146,7 @@ var (
 		defaultImageConfig: &distro.ImageConfig{
 			Locale: common.ToPtr("en_US.UTF-8"),
 		},
-		kernelOptions:       amiKernelOptions,
+		kernelOptions:       amiKernelOptions + " modprobe.blacklist=vc4",
 		defaultSize:         10 * common.GibiByte,
 		rpmOstree:           true,
 		bootable:            true,
@@ -166,6 +167,7 @@ var (
 		defaultImageConfig: &distro.ImageConfig{
 			Locale: common.ToPtr("en_US.UTF-8"),
 		},
+		kernelOptions:       "modprobe.blacklist=vc4",
 		defaultSize:         10 * common.GibiByte,
 		rpmOstree:           true,
 		bootable:            true,

pkg/distro/rhel9/images.go

@@ -405,7 +405,12 @@ func edgeRawImage(workload workload.Workload,
 	img.Users = users.UsersFromBP(customizations.GetUsers())
 	img.Groups = users.GroupsFromBP(customizations.GetGroups())
 
-	img.KernelOptionsAppend = []string{"modprobe.blacklist=vc4"}
+	// The kernel options defined on the image type are usually handled in
+	// osCustomiztions() but ostree images don't use OSCustomizations, so we
+	// handle them here separately.
+	if t.kernelOptions != "" {
+		img.KernelOptionsAppend = append(img.KernelOptionsAppend, t.kernelOptions)
+	}
 	img.Keyboard = "us"
 	img.Locale = "C.UTF-8"
 	if !common.VersionLessThan(t.arch.distro.osVersion, "9.2") || !t.arch.distro.isRHEL() {