xhci 1.0: Set transfer burst last packet count field.

The xHCI 1.0 specification defines a new isochronous TRB field, called
transfer burst last packet count (TBLPC).  This field defines the number
of packets in the last "burst" of packets in a TD.  Only SuperSpeed
endpoints can handle more than one burst, so this is set to the number for
packets in a TD for all non-SuperSpeed devices (minus one, since the field
is zero based).

This patch should have no effect on host controllers that don't advertise
the xHCI 1.0 (0x100) version number in their hci_version field.

Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>