ARM: dts: exynos: Add sound support for Odroid XU4

This patch adds support for Odroid XU4 audio. The main difference
comparing to Odroid XU3 is a missing on-board audio CODEC, only
HDMI output is supported on Odroid XU4. External CODEC could be
optionally connected to the I2S port connector.

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