firmware: arm_scmi: Set fwnode for the scmi_device

This allows fw_devlink to track and enforce supplier-consumer
dependencies for scmi_device.

Signed-off-by: Saravana Kannan <saravanak@google.com>
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Tested-by: Colin Foster <colin.foster@in-advantage.com>
Tested-by: Sudeep Holla <sudeep.holla@arm.com>
Tested-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Luca Weiss <luca.weiss@fairphone.com> # qcom/sm7225-fairphone-fp4
Link: https://lore.kernel.org/r/20230207014207.1678715-12-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>