Update default value for ALC282 for COEF.

[The update doesn't seem to have high impact on the existing machines,
 but it fixes possible issues, especially expected in BIOS changes on
 new machines, according to Realtek -- tiwai]
Signed-off-by: Kailang Yang <kailang@realtek.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>