arm64: dts: actions: Convert to new-style SPDX license identifiers

Move SPDX-License-Identifier to the top and add one for the Makefile.

Signed-off-by: Andreas Färber <afaerber@suse.de>

arm64: dts: actions: Add S700 and CubieBoard7

Add Device Trees for S700 SoC and Cubietech CubieBoard7.

Signed-off-by: Andreas Färber <afaerber@suse.de>

kbuild: handle dtb-y and CONFIG_OF_ALL_DTBS natively in Makefile.lib

If CONFIG_OF_ALL_DTBS is enabled, "make ARCH=arm64 dtbs" compiles each
DTB twice; one from arch/arm64/boot/dts/*/Makefile and the other from
the dtb-$(CONFIG_OF_ALL_DTBS) line in arch/arm64/boot/dts/Makefile.
It could be a race problem when building DTBS in parallel.

Another minor issue is CONFIG_OF_ALL_DTBS covers only *.dts in vendor
sub-directories, so this broke when Broadcom added one more hierarchy
in arch/arm64/boot/dts/broadcom/<soc>/.

One idea to fix the issues in a clean way is to move DTB handling
to Kbuild core scripts. Makefile.dtbinst already recognizes dtb-y
natively, so it should not hurt to do so.

Add $(dtb-y) to extra-y, and $(dtb-) as well if CONFIG_OF_ALL_DTBS is
enabled. All clutter things in Makefiles go away.

As a bonus clean-up, I also removed dts-dirs. Just use subdir-y
directly to traverse sub-directories.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
[robh: corrected BUILTIN_DTB to CONFIG_BUILTIN_DTB]
Signed-off-by: Rob Herring <robh@kernel.org>

kbuild: clean up *.dtb and *.dtb.S patterns from top-level Makefile

We need to add "clean-files" in Makfiles to clean up DT blobs, but we
often miss to do so.

Since there are no source files that end with .dtb or .dtb.S, so we
can clean-up those files from the top-level Makefile.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Rob Herring <robh@kernel.org>

arm64: dts: Add Actions Semi S900 and Bubblegum-96

Add Device Trees for Actions Semiconductor S900 SoC and
uCRobotics Bubblegum-96 board.

UART0/1/4/6 interrupts are guesses.

Cc: 96boards@ucrobotics.com
Signed-off-by: Andreas Färber <afaerber@suse.de>