ASoC: add AD1980 obsolete information

This codec has been obsoleted by ADI, so add appropriate warnings to the
source tree to dissuade people from using in new designs based on driver
support.

Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
diff --git a/sound/soc/blackfin/Kconfig b/sound/soc/blackfin/Kconfig
index 8ef2502..3abeedd 100644
--- a/sound/soc/blackfin/Kconfig
+++ b/sound/soc/blackfin/Kconfig
@@ -105,13 +105,18 @@
 	  Set the correct GPIO for RESET the sound chip.
 
 config SND_BF5XX_SOC_AD1980
-	tristate "SoC AD1980/1 Audio support for BF5xx"
+	tristate "SoC AD1980/1 Audio support for BF5xx (Obsolete)"
 	depends on SND_BF5XX_AC97
 	select SND_BF5XX_SOC_AC97
 	select SND_SOC_AD1980
 	help
 	  Say Y if you want to add support for SoC audio on BF5xx STAMP/EZKIT.
 
+	  Warning:
+	  Because Analog Devices Inc. discontinued the ad1980 sound chip since
+	  Sep. 2009, this ad1980 driver is not maintained, tested and supported
+	  by ADI now.
+
 config SND_BF5XX_SOC_SPORT
 	tristate