dt-bindings: pinctrl: mediatek: use - instead of _ in examples

It should be good that no use "_" is in examples. Consequently,
those nodes in certain files which have an inappropriate name containing
"_" are all being replaced with "-".

Signed-off-by: Sean Wang <sean.wang@mediatek.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: linux-gpio@vger.kernel.org
Cc: devicetree@vger.kernel.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Documentation/devicetree/bindings/pinctrl/pinctrl-mt65xx.txt

@@ -76,12 +76,12 @@ Examples:
 
 ...
 {
-	syscfg_pctl_a: syscfg_pctl_a@10005000 {
+	syscfg_pctl_a: syscfg-pctl-a@10005000 {
 		compatible = "mediatek,mt8135-pctl-a-syscfg", "syscon";
 		reg = <0 0x10005000 0 0x1000>;
 	};
 
-	syscfg_pctl_b: syscfg_pctl_b@1020c020 {
+	syscfg_pctl_b: syscfg-pctl-b@1020c020 {
 		compatible = "mediatek,mt8135-pctl-b-syscfg", "syscon";
 		reg = <0 0x1020C020 0 0x1000>;
 	};