OMAPDSS: Kconfig: Remove HDMI audio booleans from Kconfig

The booleans are not used anymore. Just select SND_OMAP_SOC_HDMI_AUDIO
to enable OMAP HDMI audio support.

Signed-off-by: Jyri Sarha <jsarha@ti.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>