Clean up useless kernel/dtb target copy

The copy of kernel as 'dtb' target is useless and likely a wrong thing
to do.  Let's clean it up to avoid the confusion.

Change-Id: I1230311ff176e6f6df74b7549039831c3b869501
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
1 file changed