[oe] initramfs image with secondary cramfs inside

[C Michael Sundius]

>
> The default is to depend on populate_staging because the output from
> that task is, in general, what other packages need in order to build.
> But you can make your recipe depend on another task if you want; try (in
> your initramfs recipe):
>
> do_fetch[depends] = "cramfs-image:do_rootfs"
>
> p.
>
> works like a charm... thank you....

mike