spmi: of: fixup generic SPMI devicetree binding example

The generic SPMI example was missing an equal sign in the assignment
of the #size-cells property.

Signed-off-by: Josh Cartwright <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

Documentation/devicetree/bindings/spmi/spmi.txt

···
 		reg = <...>;
 
 		#address-cells = <2>;
-		#size-cells <0>;
+		#size-cells = <0>;
 
 		child@0 {
 			compatible = "...";