Revert "ARM: convert build of appended dtb zImage to list of dtbs"

This reverts commit 5e9468632ea81e7d17fc9bd4457acbaffda7b370.

Tixy was seeing trouble with "make dtbs" and "make my-boards.dtb",
and found reverting this resolves the issue. So for now lets
revert this.

Reported-by: Jon Medhurst (Tixy) <tixy@linaro.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
6 files changed