kernel-yocto: Move defaults and tasks from linux-yocto.inc into bbclass
This allows the kernel-yocto bbclass to be inherited in a recipe without
needing to include linux-yocto.inc. The bbclass should stand on its own
and linux-yocto.inc does a few things which may not be desired in other
kernel recipes (such as modifying KERNEL_FEATURES).
The LINUX_VERSION_EXTENSION default is not moved as other kernel recipes
may not want this setting in place.
Signed-off-by: Paul Barker <pbarker@konsulko.com> Signed-off-by: Bruce Ashfield <bruce.ashfield@gmail.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
