ASoC: davinci: Add support for AM33xx SoC Audio

AM33xx uses same McASP IP as the Davinci Platform. This patch updates
Kconfig and makefile to enable build for McASP, PCM & Codec drivers.

Signed-off-by: Hebbar, Gururaja <gururaja.hebbar@ti.com>
Signed-off-by: Darren Etheridge <detheridge@ti.com>
Signed-off-by: Jyri Sarha <jsarha@ti.com>
Signed-off-by: Mark Brown <broonie@linaro.org>