ASoC: Merge AT91 and AVR32 support into a single atmel architecture

The Ateml AT91 and AVR32 SoC share common IP for audio and can share the
same driver code using the atmel-ssc API provided for both architectures.
Do this, creating a new unified atmel ASoC architecture to replace the
previous at32 and at91 ones.

[This was contributed as a patch series for reviewability but has been
squashed down to a single commit to help preserve both the history and
bisectability.  A small bugfix from Jukka is included.]

Tested-by: Jukka Hynninen <ext-jukka.hynninen@vaisala.com>
Signed-off-by: Sedji Gaouaou <sedji.gaouaou@atmel.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
diff --git a/sound/soc/Kconfig b/sound/soc/Kconfig
index 4dfda66..615ebf0 100644
--- a/sound/soc/Kconfig
+++ b/sound/soc/Kconfig
@@ -23,8 +23,7 @@
 	bool
 
 # All the supported Soc's
-source "sound/soc/at32/Kconfig"
-source "sound/soc/at91/Kconfig"
+source "sound/soc/atmel/Kconfig"
 source "sound/soc/au1x/Kconfig"
 source "sound/soc/pxa/Kconfig"
 source "sound/soc/s3c24xx/Kconfig"