ASoC: snd-soc-afeb9260: delete driver as board has just been removed

During the removal of all AT91 !DT boards, we removed the AFEB9260. This driver
is !DT and was only used by this board, so we delete it as well.

Reported-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>