ALSA: hda - Add missing models for Realtek codecs

Added the missing descriptions and the model names for Realtek codecs
to the documentation and the config table.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/pci/hda/patch_realtek.c b/sound/pci/hda/patch_realtek.c
index 34f6fb7..db89612 100644
--- a/sound/pci/hda/patch_realtek.c
+++ b/sound/pci/hda/patch_realtek.c
@@ -16184,6 +16184,8 @@
 	[ALC663_ASUS_MODE4] = "asus-mode4",
 	[ALC663_ASUS_MODE5] = "asus-mode5",
 	[ALC663_ASUS_MODE6] = "asus-mode6",
+	[ALC272_DELL]		= "dell",
+	[ALC272_DELL_ZM1]	= "dell-zm1",
 	[ALC662_AUTO]		= "auto",
 };