dt-bindings: gpio: mpfs-gpio: allow parsing of hog child nodes.

The SD card and eMMC on PolarFire SoC are sometimes muxed using a GPIO
by the bootloader. Add a hog child property to facilitate this.
Signed-off-by: NConor Dooley <conor.dooley@microchip.com>
Reviewed-by: NKrzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: NBartosz Golaszewski <brgl@bgdev.pl>

Documentation/devicetree/bindings/gpio/microchip,mpfs-gpio.yaml

@@ -44,6 +44,24 @@ properties:
 
   gpio-controller: true
 
+patternProperties:
+  "^.+-hog(-[0-9]+)?$":
+    type: object
+
+    additionalProperties: false
+
+    properties:
+      gpio-hog: true
+      gpios: true
+      input: true
+      output-high: true
+      output-low: true
+      line-name: true
+
+    required:
+      - gpio-hog
+      - gpios
+
 required:
   - compatible
   - reg