ASoC: rsnd: call free_irq() both DMA/PIO mode

commit 701172dc ("ASoC: rsnd: don't use devm_request_irq() for SSI")
exchanged devm_request_irq() to request_irq() for SSI, because SSI will
fallback into PIO mode if DMA doesn't work.
But, because of it, PIO mode needed to call free_irq() when removing,
not only DMA mode.
This patch call free_irq() both PIO/DMA. Otherwise, rsnd IRQ handler
will be increased if user tried many unbind/bind.

Fixes: 701172dc ("ASoC: rsnd: don't use devm_request_irq() for SSI")
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>