MFC r253532:

Fix an XHCI regression:

The Block Event Interrupts, BEI, feature does not
work like expected with the Renesas XHCI chipsets.
Revert feature.

While at it correct the TD SIZE computation in
case of Zero Length Packet, ZLP, in the end of a
multi frame USB transfer.

PR: usb/180726
Approved by: re, hrs