firmware: arm_scmi: Constify ops pointers in scmi_handle

These are never modified, so make them const to allow drivers to make
them const.

Link: https://lore.kernel.org/r/20200906230452.33410-3-rikard.falkeborn@gmail.comSigned-off-by: Rikard Falkeborn <rikard.falkeborn@gmail.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

include/linux/scmi_protocol.h

@@ -279,12 +279,12 @@ struct scmi_notify_ops {
 struct scmi_handle {
 	struct device *dev;
 	struct scmi_revision_info *version;
-	struct scmi_perf_ops *perf_ops;
-	struct scmi_clk_ops *clk_ops;
-	struct scmi_power_ops *power_ops;
-	struct scmi_sensor_ops *sensor_ops;
-	struct scmi_reset_ops *reset_ops;
-	struct scmi_notify_ops *notify_ops;
+	const struct scmi_perf_ops *perf_ops;
+	const struct scmi_clk_ops *clk_ops;
+	const struct scmi_power_ops *power_ops;
+	const struct scmi_sensor_ops *sensor_ops;
+	const struct scmi_reset_ops *reset_ops;
+	const struct scmi_notify_ops *notify_ops;
 	/* for protocol internal use */
 	void *perf_priv;
 	void *clk_priv;