ASoC: Complete Beagleboard support

Commit dc06102a

 in the asoc tree
did not include the necessary Kconfig and Makefile changes.  This patch
completes the support for Beagleboard

Signed-off-by: Steve Sakoman <steve@sakoman.com>
Acked-by: Jarkko Nikula <jarkko.nikula@nokia.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>