dt-bindings: cros-ec: Fix a typo in description

A 's/pf/of/' on rpmsg-name description.
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Acked-by: Rob Herring <robh@kernel.org>
Reviewed-by: Guenter Roeck <groeck@chromium.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20220512013921.164637-2-swboyd@chromium.org

Documentation/devicetree/bindings/mfd/google,cros-ec.yaml

@@ -57,7 +57,7 @@ properties:
   mediatek,rpmsg-name:
     description:
       Must be defined if the cros-ec is a rpmsg device for a Mediatek
-      ARM Cortex M4 Co-processor. Contains the name pf the rpmsg
+      ARM Cortex M4 Co-processor. Contains the name of the rpmsg
       device. Used to match the subnode to the rpmsg device announced by
       the SCP.
     $ref: "/schemas/types.yaml#/definitions/string"