ALSA: hda: Fix 0 dB offset for HP laptops using CX20551 (Waikiki)

ALSA: hda: Fix 0 dB offset for HP laptops using CX20551 (Waikiki)

commit 025f206c9e0f96cc41567b01c07fb852d8900da1 upstream.

BugLink: https://launchpad.net/bugs/420578
The OR has verified that his hardware distorts because of the 0 dB
offset not corresponding to the highest PCM level. Fix this by capping
said PCM level to 0 dB similarly to what we do for CX20549 (Venice).

Reported-by: Mike Pontillo <pontillo@gmail.com>
Tested-by: Mike Pontillo <pontillo@gmail.com>
Signed-off-by: Daniel T Chen <crimsun@ubuntu.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>