firmware: arm_scmi: Remove zero-length array in SCMI notifications

Substitute zero-length array defined in scmi_base_error_report with
a flexible length array definition.

Link: https://lore.kernel.org/r/20200710133919.39792-1-cristian.marussi@arm.com
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

include/linux/scmi_protocol.h

@@ -421,7 +421,7 @@ struct scmi_base_error_report {
 	u32 agent_id;
 	bool fatal;
 	u16 cmd_count;
-	u64 reports[0];
+	u64 reports[];
 };
 
 #endif /* _LINUX_SCMI_PROTOCOL_H */