dt-bindings: uniphier: add bindings for UniPhier SoC family

Socionext UniPhier SoC family

-----------------------------

Required properties in the root node:

  - compatible: should contain board and SoC compatible strings

SoC and board compatible strings:

  (sorted chronologically)

  - LD4 SoC:  "socionext,uniphier-ld4"

      - Reference Board: "socionext,uniphier-ld4-ref"

  - Pro4 SoC: "socionext,uniphier-pro4"

      - Reference Board: "socionext,uniphier-pro4-ref"

      - Ace Board:       "socionext,uniphier-pro4-ace"

      - Sanji Board:     "socionext,uniphier-pro4-sanji"

  - sLD8 SoC: "socionext,uniphier-sld8"

      - Reference Board: "socionext,uniphier-sld8-ref"

  - PXs2 SoC: "socionext,uniphier-pxs2"

      - Gentil Board:    "socionext,uniphier-pxs2-gentil"

      - Vodka Board:     "socionext,uniphier-pxs2-vodka"

  - LD6b SoC: "socionext,uniphier-ld6b"

      - Reference Board: "socionext,uniphier-ld6b-ref"

  - LD11 SoC: "socionext,uniphier-ld11"

      - Reference Board: "socionext,uniphier-ld11-ref"

      - Global Board:    "socionext,uniphier-ld11-global"

  - LD20 SoC: "socionext,uniphier-ld20"

      - Reference Board: "socionext,uniphier-ld20-ref"

      - Global Board:    "socionext,uniphier-ld20-global"

  - PXs3 SoC: "socionext,uniphier-pxs3"

      - Reference Board: "socionext,uniphier-pxs3-ref"

Example:

/dts-v1/;

/ {

	compatible = "socionext,uniphier-ld20-ref", "socionext,uniphier-ld20";

	...

};

L:	linux-arm-kernel@lists.infradead.org (moderated for non-subscribers)

T:	git git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-uniphier.git

S:	Maintained

F:	Documentation/devicetree/bindings/arm/socionext/uniphier.txt

F:	Documentation/devicetree/bindings/gpio/gpio-uniphier.txt

F:	Documentation/devicetree/bindings/pinctrl/socionext,uniphier-pinctrl.txt

F:	arch/arm/boot/dts/uniphier*