ALSA: hda - Reword information messages for BIOS auto-probing mode

The sentense "Unknown model for xxx, ..." makes people too nervous
and drives them to a direction to a wrong "fix" by giving any
mismatching model option.

Let's rephrase the messages to be more nice and easy (at least that
won't make people suspect conspiracies).

Signed-off-by: Takashi Iwai <tiwai@suse.de>