doc: dt bindings: Document Odroid X2/U3 audio subsystem bindings

Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
ASoC: samsung: Add machine driver for Odroid X2/U3

This patch adds the sound subsystem driver for Odroid-X2 and
Odroid-U3 boards. The codec works in I2S master mode; there
are two separate audio routing paths defined, as there are
differences in the signal routing between the X2 and U3 boards,
i.e. U3 uses single jack for headphones and microphone.

Signed-off-by: Chen Zhen <zhen1.chen@samsung.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
ASoC: samsung-i2s: Maintain CDCLK settings across i2s_{shutdown/startup}

Currently configuration of the CDCLK pad is being overwritten in
the i2s_shutdown() callback in order to gate the SoC output clock.
However if an ASoC machine driver doesn't restore that clock
settings each time after opening the sound device this results
in the CDCLK pin being permanently configured into input mode.
I.e. the output clock will always stay disabled.
Fix that by saving the CDCLKCON bit state in i2s_shutdown() and
and restoring it in the i2s_startup() callback.

Signed-off-by: Chen Zhen <zhen1.chen@samsung.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
ARM: dts: Add sound nodes for Odroid-X2/U3 boards

Add MAX98090 audio codec, I2S interface and the sound complex
nodes to enable audio on Odroid-X2/U3 boards.

Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>

Conflicts:
	arch/arm/boot/dts/exynos4412-odroid-common.dtsi
ARM: dts: Add configuration of audio clocks for exynos4412-odroid

This specifies the EPLL and Audio Subsystem clocks configuration
for a set up with the MAX98090 codec as an I2S master.

Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>