ARM: dts: exynos: Add support for audio over HDMI for Odroid X/X2/U3

This patch switches Odroid X/X2/U3 to use dedicated Odroid audio subsystem
DT bindings instead of the simple-card in order to add support for audio
over HDMI.

Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>