MAINTAINERS: Add entry for sound/soc/ti and update the OMAP audio support

The sound/soc/davinci and omap directories are merged under sound/soc/ti.

Add myself as maintainer and update the OMAP audio support section with the
new path and file names.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Mark Brown <broonie@kernel.org>