[ALSA] ASoC AT91 DAI modes update

This patch by Frank Mandarino updates the AT91RM9200 I2S DAI audio modes
as follows:-
 o fixes a typo in the 16k mode
 o removes experimental 24k mode
 o adds a 32k mode.

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