ARM: sunxi: Support the Nextthing GR8

The GR8 is an SoC made by Nextthing Co, loosely based on the sun5i family.

It has a number of new controllers compared to the A10s and A13 (SPDIF, I2S),
but some controllers missing too (Ethernet, less I2C, less UARTs).

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

Documentation/arm/sunxi/README

@@ -31,6 +31,8 @@ SunXi family
         + User Manual
           http://dl.linux-sunxi.org/A13/A13%20User%20Manual%20-%20v1.2%20%282013-01-08%29.pdf
 
+      - Next Thing Co GR8 (sun5i)
+
     * Dual ARM Cortex-A7 based SoCs
       - Allwinner A20 (sun7i)
         + User Manual

Documentation/devicetree/bindings/arm/sunxi.txt

@@ -14,3 +14,4 @@ using one of the following compatible strings:
   allwinner,sun8i-a83t
   allwinner,sun8i-h3
   allwinner,sun9i-a80
+  nextthing,gr8

MAINTAINERS

@@ -982,6 +982,7 @@ M:	Chen-Yu Tsai <wens@csie.org>
 L:	linux-arm-kernel@lists.infradead.org (moderated for non-subscribers)
 S:	Maintained
 N:	sun[x456789]i
+F:	arch/arm/boot/dts/ntc-gr8*
 
 ARM/Allwinner SoC Clock Support
 M:	Emilio López <emilio@elopez.com.ar>

arch/arm/mach-sunxi/sunxi.c

@@ -22,6 +22,7 @@ static const char * const sunxi_board_dt_compat[] = {
 	"allwinner,sun5i-a10s",
 	"allwinner,sun5i-a13",
 	"allwinner,sun5i-r8",
+	"nextthing,gr8",
 	NULL,
 };