mfd: max77686: Use a generic name for the PMIC node in the example

The ePAPR standard says that: "the name of a node should be somewhat
generic, reflecting the function of the device and not its precise
programming model."

So, change the max77686 binding document example to use a generic
node name instead of using the chip's name.

Suggested-by: Sergei Shtylyov <[e-mail]>
Signed-off-by: Javier Martinez Canillas <[e-mail]>
Signed-off-by: Lee Jones <[e-mail]>

Documentation/devicetree/bindings/mfd/max77686.txt

···
 
 Example:
 
-	max77686@09 {
+	max77686: pmic@09 {
 		compatible = "maxim,max77686";
 		interrupt-parent = <&wakeup_eint>;
 		interrupts = <26 0>;