Support core-image-minimal-initramfs and core-image-tiny-initramfs signatures using signing class #96
Description
The current way to do a initramfs in this layer is to use kernel-initramfs which is specific to this layer.
One way is to use an additional class to add the signing steps at the end of the do_image_* tasks.
This should allow anyone to sign is own initramfs just by adding an "inherit" in his recipe.
(I have patch for this issue, but for kirkstone branch. I may try to port it)