dt-bindings: regulator: ti,tps65132: document VIN supply

TPS65132 is powered by its VIN supply, document it.
Signed-off-by: Stanislav Jakubek <stano.jakubek@gmail.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://patch.msgid.link/ZoWxnEY944ht2EWf@standask-GA-A55M-S2HPSigned-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/regulator/ti,tps65132.yaml

@@ -23,6 +23,8 @@ properties:
   reg:
     maxItems: 1
 
+  vin-supply: true
+
 patternProperties:
   "^out[pn]$":
     type: object
@@ -65,6 +67,7 @@ examples:
         regulator@3e {
             compatible = "ti,tps65132";
             reg = <0x3e>;
+            vin-supply = <&supply>;
 
             outp {
                 regulator-name = "outp";