dt-bindings: phy: mediatek: tphy: support type switch by pericfg

Add support type switch by pericfg register between USB3, PCIe,
SATA, SGMII, this is used to replace the way through efuse or
jumper.
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Link: https://lore.kernel.org/r/1629191987-20774-1-git-send-email-chunfeng.yun@mediatek.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

Documentation/devicetree/bindings/phy/mediatek,tphy.yaml

@@ -201,6 +201,22 @@ patternProperties:
           Specify the flag to enable BC1.2 if support it
         type: boolean
 
+      mediatek,syscon-type:
+        $ref: /schemas/types.yaml#/definitions/phandle-array
+        maxItems: 1
+        description:
+          A phandle to syscon used to access the register of type switch,
+          the field should always be 3 cells long.
+        items:
+          items:
+            - description:
+                The first cell represents a phandle to syscon
+            - description:
+                The second cell represents the register offset
+            - description:
+                The third cell represents the index of config segment
+              enum: [0, 1, 2, 3]
+
     required:
       - reg
       - "#phy-cells"