Fix some recent regression issues:

1) Only multi-TD isochronous transfers should use NORMAL
type after specific type as per XHCI specification.

2) BEI bit is only available in NORMAL and ISOCHRONOUS
TRB types. Don't use this bit for other types to avoid
hardware asserts. Reserved bits should be don't care
though ...

MFC after:	1 week
PR:		usb/179342