dt-bindings: mediatek: Add bindings for mediatek MT6797 Platform

This adds dt-binding documentation for Mediatek MT6797. Only
include very basic items, gic, uart timer and cpu.
Signed-off-by: Mars Cheng <mars.cheng@mediatek.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>

Documentation/devicetree/bindings/arm/mediatek.txt

@@ -12,6 +12,7 @@ compatible: Must contain one of
    "mediatek,mt6592"
    "mediatek,mt6755"
    "mediatek,mt6795"
+   "mediatek,mt6797"
    "mediatek,mt7623"
    "mediatek,mt8127"
    "mediatek,mt8135"
@@ -38,6 +39,9 @@ Supported boards:
 - Evaluation board for MT6795(Helio X10):
     Required root node properties:
       - compatible = "mediatek,mt6795-evb", "mediatek,mt6795";
+- Evaluation board for MT6797(Helio X20):
+    Required root node properties:
+      - compatible = "mediatek,mt6797-evb", "mediatek,mt6797";
 - Evaluation board for MT7623:
     Required root node properties:
       - compatible = "mediatek,mt7623-evb", "mediatek,mt7623";

Documentation/devicetree/bindings/interrupt-controller/mediatek,sysirq.txt

@@ -9,6 +9,7 @@ Required properties:
 	"mediatek,mt8135-sysirq"
 	"mediatek,mt8127-sysirq"
 	"mediatek,mt6795-sysirq"
+	"mediatek,mt6797-sysirq"
 	"mediatek,mt6755-sysirq"
 	"mediatek,mt6592-sysirq"
 	"mediatek,mt6589-sysirq"

Documentation/devicetree/bindings/serial/mtk-uart.txt

@@ -8,6 +8,7 @@ Required properties:
   * "mediatek,mt6589-uart" for MT6589 compatible UARTS
   * "mediatek,mt6755-uart" for MT6755 compatible UARTS
   * "mediatek,mt6795-uart" for MT6795 compatible UARTS
+  * "mediatek,mt6797-uart" for MT6797 compatible UARTS
   * "mediatek,mt7623-uart" for MT7623 compatible UARTS
   * "mediatek,mt8127-uart" for MT8127 compatible UARTS
   * "mediatek,mt8135-uart" for MT8135 compatible UARTS