Fix the max number of codecs detected by HD-intel (and compatible)
controllers.

ATI controllers may have up to 4 codecs while ICH up to 3.
Now max codecs is defined according to the driver type, either 3 or 4.
Currently 4 is set only to ATI chips.  Other might need the same
change, too.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>