[ALSA] ASoC AT91RM92000 eti_b1 machine support

This patch adds support for the Endrelia ETI_B1 machine using the WM8731
codec and the AT91RM9200 platform.

Signed-off-by: Frank Mandarino <fmandarino@endrelia.com>
Signed-off-by: Liam Girdwood <liam.girdwood@wolfsonmicro.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>