Set the maximum exit latency to 0 for XHCI USB 3.0 devices, because we
don't implement link power management, LPM.

This fixes error code XHCI_TRB_ERROR_BANDWIDTH for isochronous USB 3.0
transactions.

Submitted by: Horse Ma <Shichun.Ma@dell.com>
MFC after: 1 week
Sponsored by: Mellanox Technologies