ARM: OMAP: devices: Register platform devices for HDMI audio

Add platform registration for the devices HDMI audio support. The
omap-hdmi-audio-dai platform device is to be used by the ASoC HDMI
CPU DAI driver. The omap-hdmi-audio platform device is to be used
by the ASoC HDMI machine driver that links together the ASOC CPU DAI,
ASoC plaform and ASoC codec drivers.

Signed-off-by: Ricardo Neri <ricardo.neri@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>