firmware: arm_scmi: Add flags field to xfer

Add a 'flags' field to xfer and define a flagbit and related macro to easily
identify xfers originated from the raw transmissions.
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Tested-by: Florian Fainelli <f.fainelli@gmail.com>
Tested-by: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lore.kernel.org/r/20230118121426.492864-5-cristian.marussi@arm.comSigned-off-by: Sudeep Holla <sudeep.holla@arm.com>

drivers/firmware/arm_scmi/protocols.h

@@ -115,6 +115,7 @@ struct scmi_msg_hdr {
  *	    - SCMI_XFER_SENT_OK -> SCMI_XFER_RESP_OK [ -> SCMI_XFER_DRESP_OK ]
  *	    - SCMI_XFER_SENT_OK -> SCMI_XFER_DRESP_OK
  *	      (Missing synchronous response is assumed OK and ignored)
+ * @flags: Optional flags associated to this xfer.
  * @lock: A spinlock to protect state and busy fields.
  * @priv: A pointer for transport private usage.
  */
@@ -135,6 +136,9 @@ struct scmi_xfer {
 #define SCMI_XFER_RESP_OK	1
 #define SCMI_XFER_DRESP_OK	2
 	int state;
+#define SCMI_XFER_FLAG_IS_RAW	BIT(0)
+#define SCMI_XFER_IS_RAW(x)	((x)->flags & SCMI_XFER_FLAG_IS_RAW)
+	int flags;
 	/* A lock to protect state and busy fields */
 	spinlock_t lock;
 	void *priv;