dt-bindings: pinctrl: renesas,pfc: align example GPIO hog name with dtschema

The convention for node names is to use hyphens, not underscores.
dtschema expects GPIO hogs to end with 'hog' suffix.  Adjust the example
DTS in the binding.  No changes to binding itself.
Reported-by: Rob Herring <robh@kernel.org>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Link: https://lore.kernel.org/r/20200928184515.7345-1-krzk@kernel.orgSigned-off-by: Linus Walleij <linus.walleij@linaro.org>

Documentation/devicetree/bindings/pinctrl/renesas,pfc.yaml

@@ -148,7 +148,7 @@ examples:
                 <&irqpin3 4 0>, <&irqpin3 5 0>, <&irqpin3 6 0>, <&irqpin3 7 0>;
             power-domains = <&pd_c5>;
 
-            lcd0_mux {
+            lcd0-mux-hog {
                     /* DBGMD/LCDC0/FSIA MUX */
                     gpio-hog;
                     gpios = <176 0>;