usb: wusbcore: add support for isoc out transfers

This patch adds support for isochronous out transfers to the HWA.  The
primary changes are:

1.  Add a isoc_pack_desc_urb field to struct wa_seg.  This urb is used
to send the isochronous packet info message to the HWA which describes
the isoc data segment(s) that will be sent as the payload of the
transfer request.

2.  Use the URB iso_frame_desc field to populate the isochronous packet
info message and data segments sent to the HWA.

3.  After the data is sent and transfer result is returned from the
HWA, read the isoc packet status message from the HWA.  The contents of
the isoc packet status message are used to set the iso_frame_desc
status and actual_length fields in the original isoc URB.  This feature
required the addition of a some state tracking variables in struct wahc
so the dti_urb knows what type of packet it expects to receive next.

Signed-off-by: Thomas Pugliese <thomas.pugliese@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>