For sdk related targets, the greybus build will error out due to missing
kernel dependency. Let's avoid those targets by checking TARGET_NO_KERNEL.
Signed-off-by: Vishal Bhoj <vishal.bhoj@linaro.org> Signed-off-by: Michael Scott <michael.scott@linaro.org> Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>