ALSA: hda - Fix digital beep tone calculation

The digital beep tone is calculated in two different ways depending
on the codec chip.  The standard one is using a divider, and another
one is a linear tone for IDT/STAC codecs.  Currently, only the
latter type is used for all codecs, which resulted in a wrong tone
pitch.

This patch adds the calculation of the standard HD-audio type.
Also clean-up the fields in hda_beep struct.

Reference: bko#13162
	http://bugzilla.kernel.org/show_bug.cgi?id=13162



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