sunxi: add a64 watchdog support

Backport A64 watchdog DTS change to 4.14 kernel.

Signed-off-by: Oskari Lemmela <oskari@lemmela.net>

target/linux/sunxi/patches-4.14/040-arm64-dts-allwinner-a64-Add-watchdog.patch

@@ -0,0 +1,54 @@
+From d41850437c364ef7aba9bc25c1c701699d0240e0 Mon Sep 17 00:00:00 2001
+From: Harald Geyer <harald@ccbib.org>
+Date: Thu, 15 Mar 2018 16:25:07 +0000
+Subject: [PATCH] arm64: dts: allwinner: a64: Add watchdog
+
+Add a watchdog node for the A64, automatically enabled on all boards.
+Since the device is compatible with an existing driver, we only reserve
+a new compatible string to be used together with the fall back.
+Tested on Olimex Teres-I.
+
+Signed-off-by: Harald Geyer <harald@ccbib.org>
+Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
+---
+ Documentation/devicetree/bindings/watchdog/sunxi-wdt.txt | 6 ++++--
+ arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi            | 7 +++++++
+ 2 files changed, 11 insertions(+), 2 deletions(-)
+
+diff --git a/Documentation/devicetree/bindings/watchdog/sunxi-wdt.txt b/Documentation/devicetree/bindings/watchdog/sunxi-wdt.txt
+index 62dd5baad70e..04fc368d828f 100644
+--- a/Documentation/devicetree/bindings/watchdog/sunxi-wdt.txt
++++ b/Documentation/devicetree/bindings/watchdog/sunxi-wdt.txt
+@@ -2,8 +2,10 @@ Allwinner SoCs Watchdog timer
+ 
+ Required properties:
+ 
+-- compatible : should be either "allwinner,sun4i-a10-wdt" or
+-               "allwinner,sun6i-a31-wdt"
++- compatible : should be one of
++	"allwinner,sun4i-a10-wdt"
++	"allwinner,sun6i-a31-wdt"
++	"allwinner,sun50i-a64-wdt","allwinner,sun6i-a31-wdt"
+ - reg : Specifies base physical address and size of the registers.
+ 
+ Example:
+diff --git a/arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi b/arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi
+index 64e452a758fa..8401e7f887ff 100644
+--- a/arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi
++++ b/arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi
+@@ -665,5 +665,12 @@
+ 			#address-cells = <1>;
+ 			#size-cells = <0>;
+ 		};
++
++		wdt0: watchdog@1c20ca0 {
++			compatible = "allwinner,sun50i-a64-wdt",
++				     "allwinner,sun6i-a31-wdt";
++			reg = <0x01c20ca0 0x20>;
++			interrupts = <GIC_SPI 25 IRQ_TYPE_LEVEL_HIGH>;
++		};
+ 	};
+ };
+-- 
+2.17.1
+