ASoC: imx: Fix build warning of unused 'card' variable

Fixes the following warning:

  CC      sound/soc/imx/imx-pcm-fiq.o
sound/soc/imx/imx-pcm-fiq.c: In function 'imx_pcm_fiq_new':
sound/soc/imx/imx-pcm-fiq.c:243: warning: unused variable 'card'
  CC      sound/soc/imx/imx-pcm-dma-mx2.o
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

sound/soc/imx/imx-pcm-fiq.c

@@ -240,7 +240,6 @@ static int ssi_irq = 0;
 
 static int imx_pcm_fiq_new(struct snd_soc_pcm_runtime *rtd)
 {
-	struct snd_card *card = rtd->card->snd_card;
 	struct snd_soc_dai *dai = rtd->cpu_dai;
 	struct snd_pcm *pcm = rtd->pcm;
 	int ret;