qcacmn: Flush srng tp and hp only for flush event

Currently after runtime resume all SW2TCL data and reo cmd
srng rings hp and tp value are flushed. In case of IPA
offload case SW2TCL3 righ hp value will be updated by IPA
and not by host. In case of runtime pm enable host is
setting the value to zero as part of runtime resume which
results in incorrect hp value of SW2TCL3. As part of this
change set flush event for rings which are accessed by host
during link down state and after runtime resume flush the
rings for which flush event is set.

Change-Id: I5c9afa708277cf3a6e6d5ef99447bc21f88cfdcf
CRs-Fixed: 2514621

hal/wifi3.0/hal_srng.c

@@ -726,6 +726,8 @@ void *hal_srng_setup(void *hal_soc, int ring_type, int ring_num,
 
 	SRNG_LOCK_INIT(&srng->lock);
 
+	srng->srng_event = 0;
+
 	srng->initialized = true;
 
 	return (void *)srng;