ASoC: samsung: Add support for HDMI audio on TM2 board

This patch defines I2S1 - HDMI DAI link and implements related
hw_params callback. The AUD PLL frequency is configured through
the CLK_SCLK_I2S1 leaf clock, the exynos5433 clock tree
definitions are updated in a separate patch.

The device tree parsing part is changed is a way it supports older
DTBs with just a single CPU DAI specified, without the HDMI link.

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