regulator: dt-bindings: microchip,mcp16502: Add voltage input supply documentation

Update the yaml schema with info about input supply phandle for
each buck and ldo according with the PMIC MCP16502 Datasheet.
Signed-off-by: Andrei Simion <andrei.simion@microchip.com>
Link: https://patch.msgid.link/20240812135231.43744-3-andrei.simion@microchip.comSigned-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/regulator/microchip,mcp16502.yaml

@@ -28,6 +28,21 @@ properties:
   reg:
     maxItems: 1
 
+  lvin-supply:
+    description: Input supply phandle for LDO1 and LDO2
+
+  pvin1-supply:
+    description: Input supply phandle for VDD_IO (BUCK1)
+
+  pvin2-supply:
+    description: Input supply phandle for VDD_DDR (BUCK2)
+
+  pvin3-supply:
+    description: Input supply phandle for VDD_CORE (BUCK3)
+
+  pvin4-supply:
+    description: Input supply phandle for VDD_OTHER (BUCK4)
+
   regulators:
     type: object
     additionalProperties: false
@@ -68,6 +83,11 @@ examples:
         pmic@5b {
             compatible = "microchip,mcp16502";
             reg = <0x5b>;
+            lvin-supply = <&reg_5v>;
+            pvin1-supply = <&reg_5v>;
+            pvin2-supply = <&reg_5v>;
+            pvin3-supply = <&reg_5v>;
+            pvin4-supply = <&reg_5v>;
 
             regulators {
                 VDD_IO {