iso support

[Duncan Sands]

Hi Matthieu, actually I think I may put the flags parameter in
struct usbatm_data, and remove it from bind.

> I was thinking about :
> #define IGNORE_ELISEQ           0x02 /* ignore ELISEQ errors */

I will reread the emails about this, because I've forgotten what it was
all about.

> #define ISO_PACKET_MAX_SIZE     0x04 /* don't try to use iso packets 
> that have a size != max_packet_size *

as far as I can see, the iso packet size has to always be equal to
a multiple of the endpoint maxpacket size.

Ciao,

D.