Modules: Documentation,USB generic driver

The patch adds the 'device_setup' module parameter and a specific
quirk to correctly initialize the audiophile usb device: this fixes
the distorted sound bug on the Analog capture port. Backward
compatibility is achieved by simply omitting the new parameter.
Signed-off-by: NThibault LE MEUR <Thibault.LeMeur@supelec.fr>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>