This patch adds the support for isochronous pipe.

A new module parameter is added to select iso mode.  It is set to iso by
default because bulk mode doesn't work well at high speed rate (>3 Mbps
for upload).

We use UDSL_IGNORE_EILSEQ flags because ADI firmware doesn't reply to
ISO IN when it has nothing to send [1].

[1]
from cypress datasheet :

The ISOSEND0 Bit (bit 7 in the USBPAIR Register) is used when the EZ-USB
FX chip receives an isochronous IN token while the IN FIFO is empty. If
ISOSEND0=0 (the default value), the USB core does not respond to the IN
token. If ISOSEND0=1, the USB core sends a zero-length data packet in
response to the IN token. The action to take depends on the overall
system design. The ISOSEND0 Bit applies to all of the isochronous IN
endpoints, IN-8 through IN-15.
Signed-off-by: Matthieu CASTET <castet.matthieu@free.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>