[ALSA] hda-codec - Rename HP model-specific quirks

Rename ALC888_HP_NETTLE and ALC888_HP_LUCKNOW models to the more generic
names ALC888_6ST_HP and ALC888_3ST_HP since HP seems to be consistent
in the wiring of their 3stack and 6stack ALC888-based systems.

Signed-off-by: Claudio Matsuoka <cmatsuoka@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>

Documentation/sound/alsa/ALSA-Configuration.txt

@@ -861,8 +861,8 @@ Prior to version 0.9.0rc4 options had a 'snd_' prefix. This was removed.
 	  lenovo-101e	Lenovo 101E
 	  lenovo-nb0763	Lenovo NB0763
 	  lenovo-ms7195-dig Lenovo MS7195
-	  hp-nettle	HP Nettle
-	  hp-lucknow	HP Lucknow
+	  6stack-hp	HP machines with 6stack (Nettle boards)
+	  3stack-hp	HP machines with 3stack (Lucknow, Samba boards)
 	  auto		auto-config reading BIOS (default)
 
 	ALC861/660