ASoC: fsi: use devm_request_irq()

This patch uses devm_request_irq() instead of request_irq()
and removed free_irq() from driver

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