The current yocto-bsp help text simply tells the user that meta-intel is also needed in addition to the BSP layer. It should be more explicit about exactly what's needed, should be added to the usage text as well, and yocto-kernel should explicitly look for this case and error if meta-intel isn't found. Ideally this should be generic enough to allow other layers to be checked for as well.
I posted a fix to the help text for this. I think detecting that meta-intel isn't in BBLAYERS for the user is something that needs a little more thought as to a general solution that wouldn't end up being layer-specific.
http://git.yoctoproject.org/cgit/cgit.cgi/poky/commit/?id=3b78ad8041e0ea232b8363e120595cab85b30507