dt-bindings: pinctrl: qcom,tlmm-common: add common check for function

Certain pins, like SDcard related, do not have functions and such should
not be required.  Add a check for this in common Qualcomm TLMM pin
controller schema.
Reviewed-by: Bjorn Andersson <andersson@kernel.org>
Reviewed-by: Stephan Gerhold <stephan@gerhold.net>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20221016170035.35014-8-krzysztof.kozlowski@linaro.orgSigned-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

Documentation/devicetree/bindings/pinctrl/qcom,tlmm-common.yaml

@@ -65,10 +65,6 @@ additionalProperties: true
 
 $defs:
   qcom-tlmm-state:
-    allOf:
-      - $ref: pincfg-node.yaml#
-      - $ref: pinmux-node.yaml#
-
     properties:
       drive-strength:
         enum: [2, 4, 6, 8, 10, 12, 14, 16]
@@ -82,5 +78,21 @@ $defs:
       output-high: true
       output-low: true
 
+    allOf:
+      - $ref: pincfg-node.yaml#
+      - $ref: pinmux-node.yaml#
+
+      - if:
+          properties:
+            pins:
+              items:
+                pattern: "^gpio"
+        then:
+          required:
+            - function
+        else:
+          properties:
+            function: false
+
     additionalProperties: true
 ...