The current rules have the .dtb files build in a different directory
from the .dts files. This patch changes c6x to use the generic dtb
rule which builds .dtb files in the same directory as the source .dts.

This requires moving parts of arch/c6x/boot/Makefile into newly created
arch/c6x/boot/dts/Makefile, and updating arch/c6x/Makefile to call the
new Makefile. linked_dtb.S is also moved into boot/dts/ since it's used
by rules that were moved.
Acked-by: Mark Salter <msalter@redhat.com>
Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
Cc: linux-c6x-dev@linux-c6x.org
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Rob Herring <rob.herring@calxeda.com>

This hooks dtc into Kbuild's dependency system.

Thus, for example, "make dtbs" will rebuild tegra-harmony.dtb if only
tegra20.dtsi has changed yet tegra-harmony.dts has not. The previous
lack of this feature recently caused me to have very confusing "git
bisect" results.

For ARM, it's obvious what to add to $(targets). I'm not familiar enough
with other architectures to know what to add there. Powerpc appears to
already add various .dtb files into $(targets), but the other archs may
need something added to $(targets) to work.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Mark Salter <msalter@redhat.com>

Original port to early 2.6 kernel using TI COFF toolchain.
Brought up to date by Mark Salter <msalter@redhat.com>
Signed-off-by: Aurelien Jacquiot <a-jacquiot@ti.com>
Signed-off-by: Mark Salter <msalter@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>