dt/bindings: Correct clk binding example for PIC32 pinctrl

Update binding example based on new clock binding scheme.
[1] Documentation/devicetree/bindings/clock/microchip,pic32.txt

Signed-off-by: Purna Chandra Mandal <[e-mail]>
Acked-by: Rob Herring <[e-mail]>
Cc: Linus Walleij <[e-mail]>
Cc: Kumar Gala <[e-mail]>
Cc: Ian Campbell <[e-mail]>
Cc: Joshua Henderson <[e-mail]>
Cc: Mark Rutland <[e-mail]>
Cc: [e-mail]
Cc: [e-mail]
Cc: [e-mail]
Patchwork: https://patchwork.linux-mips.org/patch/13266/
Signed-off-by: Ralf Baechle <[e-mail]>

Documentation/devicetree/bindings/pinctrl/microchip,pic32-pinctrl.txt

···
 	#size-cells = <1>;
 	compatible = "microchip,pic32mzda-pinctrl";
 	reg = <0x1f801400 0x400>;
-	clocks = <&PBCLK1>;
+	clocks = <&rootclk PB1CLK>;
 
 	pinctrl_uart2: pinctrl_uart2 {
 		uart2-tx {