msm: ipa4: increase event channel ref count for non-coalescing pipe

While configuring coalescing pipe channel increasing event channel
reference count causing the null pointer dereference during WAN consumer
pipe configuration. Added changes to increase event channel ref count
only for non-coalescing pipe.

Change-Id: I1f29e636b85296115a0cbe145c5239ae2969f41e
Signed-off-by: Ashok Vuyyuru <avuyyuru@codeaurora.org>