ASoC: samsung: i2s: Let runtime PM operations to control op_clk too

This patch adds handling of parent operational clock to runtime PM
callbacks. This way it is ensured that when I2S module is in runtime
suspended state, all its parent clocks are disabled and unprepared.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Mark Brown <broonie@kernel.org>