xhci: hsic: Fix bug in handling events in event ring segment

After handling all the events in the event ring, xhci event
handler needs to get called one more time to exit from event
handling. If number of events posted in the ring is same as
max_event_to_handle xhci irq bottom half handler unnecessarily
scheduling tasklet again. This causes unclocked register access
if tasklet gets scheduled after hsic goes to low power mode. Fix
the bug by not scheduling tasklet again if cycle state transition
happened for event ring.

CRs-Fixed: 711403
Change-Id: I0a951c27160f8067abac49b60935bbbbbd99d9a4
Signed-off-by: Hemant Kumar <hemantk@codeaurora.org>
Signed-off-by: Azhar Shaikh <azhars@codeaurora.org>