Add ppc64le variant for Cloud-Base-Generic

This allows building cloud images for POWER systems.

components/boot.xml

@@ -10,6 +10,7 @@
 		<package name="grub2-efi-x64-modules" arch="x86_64"/>
 		<package name="grub2-pc" arch="x86_64"/>
 		<package name="grub2-pc-modules" arch="x86_64"/>
+		<package name="grub2-ppc64le" arch="ppc64le"/>
 		<package name="grubby"/>
 		<package name="shim-signed-aa64" arch="aarch64"/>
 		<package name="shim-signed-x64" arch="x86_64"/>