ASoC: fsi: fsi_set_master_clk() was called from fsi_hw_xxx() only

Current FSI driver is using fsi_set_master_clk() if it needs system clock.
But this function was called from
fsi_hw_shutdown()/fsi_dai_trigger()/fsi_resume() without a sense of unity.
Because of this, sound playback after suspend failed sometimes.
To keep consistency, fsi_master_clk() was called from
fsi_hw_start/stop() only now.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>