dt-bindings: firmware: arm,scmi: Update examples for protocol@13

Recently we extended the binding for protocol@13 to allow it to be modelled
as a generic performance domain. In a way to promote using the new binding,
let's update the examples.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20240403111106.1110940-1-ulf.hansson@linaro.orgSigned-off-by: Sudeep Holla <sudeep.holla@arm.com>

Documentation/devicetree/bindings/firmware/arm,scmi.yaml

@@ -355,7 +355,7 @@ examples:
 
             scmi_dvfs: protocol@13 {
                 reg = <0x13>;
-                #clock-cells = <1>;
+                #power-domain-cells = <1>;
 
                 mboxes = <&mhuB 1 0>,
                          <&mhuB 1 1>;
@@ -468,7 +468,7 @@ examples:
                 reg = <0x13>;
                 linaro,optee-channel-id = <1>;
                 shmem = <&cpu_optee_lpri0>;
-                #clock-cells = <1>;
+                #power-domain-cells = <1>;
             };
 
             scmi_clk0: protocol@14 {