ASoC: samsung: i2s: Move clk_get() to platform driver probe()

Acquire the I2S interface clock in driver probe() callback
as it's a per-device not a per-DAI clock. While at it switch
to the resource managed clk_get().

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