ASoC: rsnd: add missing .irq callback for DMA

commit b5b442abd9d5 ("ASoC: rsnd: add .irq callback") added .irq callback
but SSI DMA is missing it. This patch adds it.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
diff --git a/sound/soc/sh/rcar/ssi.c b/sound/soc/sh/rcar/ssi.c
index 90c3f58..b1a29e2 100644
--- a/sound/soc/sh/rcar/ssi.c
+++ b/sound/soc/sh/rcar/ssi.c
@@ -694,6 +694,7 @@
 	.quit	= rsnd_ssi_quit,
 	.start	= rsnd_ssi_start,
 	.stop	= rsnd_ssi_stop,
+	.irq	= rsnd_ssi_irq,
 	.fallback = rsnd_ssi_fallback,
 	.hw_params = rsnd_ssi_hw_params,
 };