As the subject indicates, meta-intel is modifying a recipe without using a machine or common override, so changes occur to the build just by including its layer, which isn't what we want from a BSP layer. If the change is generic, it belongs in oe-core, and if not, it needs to be conditional.
Patch to OE-Core to add the firmware blob, once that's merged a patch to meta-intel will be merged.
Merged into OE-Core http://git.yoctoproject.org/cgit/cgit.cgi/poky/commit/?id=c0238cb902054296025446ed41a98bf4ed89dd04 Mergedinto meta-intel http://git.yoctoproject.org/cgit/cgit.cgi/meta-intel/commit/?id=53f25dc1e2469635ed001eb065db9abeacc7bde2