Linux MIPS uses <soc-name>_<board-name>.dts board dts-file
naming scheme so use it in barebox too.

Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

This commit is based on Sascha's ARM commits:

    commit a9e7e68
    Author: Sascha Hauer <s.hauer@pengutronix.de>
    Date:   Fri Dec 11 08:02:02 2015 +0100

        ARM: dts: Add *.dtb.lzo to clean files

    commit f5b552f
    Author: Sascha Hauer <s.hauer@pengutronix.de>
    Date:   Fri May 9 09:11:49 2014 +0200

        ARM: dts: Add generated files to clean rule

Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

To build an object file from a device tree currently we currently
have to add them to the Makefile twice, once to dtb-y and once to
obj-y. This patch introduces obj-dtb-y and pbl-dtb-y to directly
compile a device tree object file for inclusion in the barebox binary
or the pbl respectively.
The now unneeded dtb-y targets are removed.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Add intermediate .S files to .SECONDARY. Otherwise make deletes them
and regenerates them each build.
Also remove KBUILD_DTBS since the make system descends in dts/ anyway.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Otherwise a rebuild of the dtb file is triggered each build.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>