ASoC: samsung: i2s: Add clock provider for the I2S internal clocks

This patch adds clock provider (currently only for DT platforms) for
the CODECLKO (CDCLK) gate, RCLKSRC mux and RCLK pre-scaler divider
divider clock. Those all tree clock are only available in the IIS
Multi Audio Interface (I2S0), the regular IIS Bus Interface has only
CDCLK gate clock.

The motivation behind this patch is to expose the I2S internal clocks
which are currently controlled through set_sysclk() through the clk
API, so dedicated sound machine driver per each board can be avoided.

The intention is also to fix the CDCLK gating issue reported by
Daniel Drake:
http://mailman.alsa-project.org/pipermail/alsa-devel/2014-September/081753.html



This patch also reverts commit b97c60ab
("ASoC: samsung-i2s: Maintain CDCLK settings across i2s_{shutdown/
startup}") The problem that commit attempted to solve only affects
the Odroid X2/U3, which doesn't configure the CDCLK clock in
struct snd_soc_dai_ops hw_params callback and the issue should be
now resolved by using clk API, i.e. having the codec enabling/
disabling the CDCLK clock as required.

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