If the user has set their own value for IMAGE_FSTYPES, they may have
disabled the cpio.gz image type, preventing the initramfs from being
produced in the format that image-live.bbclass expects; so force
IMAGE_FSTYPES to cpio.gz within the initramfs image recipe.
Signed-off-by: Paul Eggleton <paul.eggleton@linux.intel.com>
Prepend cpio.gz instead
