regulator: dt-bindings: fixed-regulator: allow gpios property

'gpios' is in general preferred even for single GPIO specifiers and
there are DTS boards using it (exynos4412-p4note.dtsi), so allow both
versions.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20230120133010.299797-1-krzysztof.kozlowski@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/regulator/fixed-regulator.yaml

@@ -35,6 +35,10 @@ allOf:
       required:
         - power-domains
         - required-opps
+  - not:
+      required:
+        - gpio
+        - gpios
 
 properties:
   compatible:
@@ -49,6 +53,9 @@ properties:
     description: gpio to use for enable control
     maxItems: 1
 
+  gpios:
+    maxItems: 1
+
   clocks:
     description:
       clock to use for enable control. This binding is only available if