ARM: OMAP2+: omap2plus_defconfig: enable twl4030 SoC audio

Many TI OMAP SoC based boards that uses twl4030 as codec have
been updated to use the unified audio driver (omap-twl4030)
since they have similar audio setup.

So, is good to have it built to add audio support to these boards.

Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Acked-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>