ALSA: snd_usb_caiaq: give better shortname

If not passed as module option, provide an own card ID with the newly
introduced snd_set_card_id() call.

This will prevent ALSA from calling choose_default_name() which only
takes the last part of a name containing whitespaces. This for example
caused 'Audio 4 DJ' to be shortened to 'DJ', which was not very
descriptive.

The implementation now takes the short name and removes all whitespaces
from it which is much nicer.

Signed-off-by: Daniel Mack <daniel@caiaq.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>