Add audio support for the Atmel AT91SAM9G20ek board(uing wolfson 8731).
It is based on the former eti_b1_wm8731.c file, using the atmel scc API.
Signed-off-by: NSedji Gaouaou <sedji.gaouaou@atmel.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>