ALSA: virtuoso: add partial Xonar Xense support

This patch adds partial support for the Xonar Xense.

[trivial coding style fixes by tiwai]

Signed-off-by: Harley Griggs <hgriggs@posteo.co.uk>
Acked-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>