For multilib and other uses of classextend, we don't want any
dependencies on kernel packages to be extended since there should only
be one kernel variant.
Fixes [YOCTO #2918] (where kernel-dev was being extended.)
(From OE-Core rev: b684c0f0d5d93f5147dee79951647eb3ddf4c840)
Signed-off-by: Paul Eggleton <paul.eggleton@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>