USB Audio Class v2.0 compliant devices have different descriptors and a
different way of setting/getting min/max/res/cur properties. This patch
adds support for them.
Signed-off-by: NDaniel Mack <daniel@caiaq.de>
Cc: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>