regulator: dt-bindings: samsung,s2mps14: add lost samsung,ext-control-gpios

The samsung,ext-control-gpios property was lost during conversion to DT
schema:

  exynos3250-artik5-eval.dtb: pmic@66: regulators:LDO11: Unevaluated properties are not allowed ('samsung,ext-control-gpios' was unexpected)

Fixes: ea98b9eba0 ("regulator: dt-bindings: samsung,s2m: convert to dtschema")
Cc: <stable@vger.kernel.org>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20230120131447.289702-1-krzysztof.kozlowski@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/regulator/samsung,s2mps14.yaml

@@ -19,8 +19,8 @@ description: |
   additional information and example.
 
 patternProperties:
-  # 25 LDOs
-  "^LDO([1-9]|[1][0-9]|2[0-5])$":
+  # 25 LDOs, without LDO10-12
+  "^LDO([1-9]|1[3-9]|2[0-5])$":
     type: object
     $ref: regulator.yaml#
     unevaluatedProperties: false
@@ -30,6 +30,23 @@ patternProperties:
     required:
       - regulator-name
 
+  "^LDO(1[0-2])$":
+    type: object
+    $ref: regulator.yaml#
+    unevaluatedProperties: false
+    description:
+      Properties for single LDO regulator.
+
+    properties:
+      samsung,ext-control-gpios:
+        maxItems: 1
+        description:
+          LDO10, LDO11 and LDO12 can be configured to external control over
+          GPIO.
+
+    required:
+      - regulator-name
+
   # 5 bucks
   "^BUCK[1-5]$":
     type: object