ALSA: hda: Add STAC_DELL_M4_3 quirk

Added STAC_DELL_M4_3 quirk for Dell systems, also reorganized the
board config switch to assign number of digital muxes, microphones,
and SPDIF muxes via the PCI quirk defined.

Signed-off-by: Matthew Ranostay <mranostay@embeddedalley.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/Documentation/sound/alsa/ALSA-Configuration.txt b/Documentation/sound/alsa/ALSA-Configuration.txt
index e0e54a2..147f176 100644
--- a/Documentation/sound/alsa/ALSA-Configuration.txt
+++ b/Documentation/sound/alsa/ALSA-Configuration.txt
@@ -1072,6 +1072,7 @@
 	  ref		Reference board
 	  dell-m4-1	Dell desktops
 	  dell-m4-2	Dell desktops
+	  dell-m4-3	Dell desktops
 
 	STAC92HD73*
 	  ref		Reference board