ASoC: omap: Remove obsolete HDMI audio code and Kconfig options

Removes omap-hdmi DAI driver, omap-hdmi-card driver, the related
Kconfig options, and Makefile entries. The HDMI DAI drivers has been
integrated directly to OMAP4+ HDMI drivers and simple-card driver is
used instead of omap-hdmi-card driver.

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