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.org


Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>