kernel-yocto: propagate in tree defconfigs to WORKDIR
As reported by Steffen Pankratz <Steffen.Pankratz@elektrobit.com>, the
previous logic of KBUILD_DEFCONFIG processing would not propagate an in
tree defcofig to WORKDIR if one was not already present.
We fix the propagation by copying the in tee config if a defconfig is
not already in WORKDIR.
Additionally we only warn (versus copying) if an in tree configuration
is specified, is different than the WORKDIR version and isn't copied.
Signed-off-by: Bruce Ashfield <bruce.ashfield@windriver.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
