Currently an isoc URB is divided into multiple TDs, and every TD will
trigger an interrupt when it's processed. However, software can schedule
multiple TDs at a time, and it only needs an interrupt every URB.

xHCI 1.0 introduces the Block Event Interrupt(BEI) flag which allows Normal
and Isoch Transfer TRBs to place an Event TRB on an Event Ring but not
assert an intrrupt to the host, and the interrupt rate is significantly
reduced and the system performance is improved.
Signed-off-by: NAndiry Xu <andiry.xu@amd.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>