msm: ADSPRPC: Add subsystem states for restart, up and down

Current subsystem state flag cannot define all state of the subsystem.
Different handling might be needed for different subsystem states.
Add multiple subsystem state support.

Change-Id: Id091dfded583c8cd7e95c0d306de6dd34b03485d
Acked-by: Santosh Sakore <ssakore@qti.qualcomm.com>
Signed-off-by: Vamsi Krishna Gattupalli <quic_vgattupa@quicinc.com>

dsp/adsprpc_shared.h

@@ -903,7 +903,7 @@ struct fastrpc_channel_ctx {
 	int in_hib;
 	void *handle;
 	uint64_t prevssrcount;
-	int issubsystemup;
+	int subsystemstate;
 	int vmid;
 	struct secure_vm rhvm;
 	void *rh_dump_dev;