Document: DT: Add bindings for mediatek MT6755 SoC Platform

This adds DT binding documentation for Mediatek MT6755.
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

@@ -10,6 +10,7 @@ compatible: Must contain one of
    "mediatek,mt6580"
    "mediatek,mt6589"
    "mediatek,mt6592"
+   "mediatek,mt6755"
    "mediatek,mt6795"
    "mediatek,mt7623"
    "mediatek,mt8127"
@@ -31,6 +32,9 @@ Supported boards:
 - Evaluation board for MT6592:
     Required root node properties:
       - compatible = "mediatek,mt6592-evb", "mediatek,mt6592";
+- Evaluation phone for MT6755(Helio P10):
+    Required root node properties:
+      - compatible = "mediatek,mt6755-evb", "mediatek,mt6755";
 - Evaluation board for MT6795(Helio X10):
     Required root node properties:
       - compatible = "mediatek,mt6795-evb", "mediatek,mt6795";

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

@@ -9,6 +9,7 @@ Required properties:
 	"mediatek,mt8135-sysirq"
 	"mediatek,mt8127-sysirq"
 	"mediatek,mt6795-sysirq"
+	"mediatek,mt6755-sysirq"
 	"mediatek,mt6592-sysirq"
 	"mediatek,mt6589-sysirq"
 	"mediatek,mt6582-sysirq"

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

@@ -6,6 +6,7 @@ Required properties:
   * "mediatek,mt6580-uart" for MT6580 compatible UARTS
   * "mediatek,mt6582-uart" for MT6582 compatible UARTS
   * "mediatek,mt6589-uart" for MT6589 compatible UARTS
+  * "mediatek,mt6755-uart" for MT6755 compatible UARTS
   * "mediatek,mt6795-uart" for MT6795 compatible UARTS
   * "mediatek,mt7623-uart" for MT7623 compatible UARTS
   * "mediatek,mt8127-uart" for MT8127 compatible UARTS