ASoC: omap-dmic: Do not use platform_get_resource_byname() for DMA

The DMA resource no longer available via this API when booting with DT.
DMIC is only available on OMAP4/5 and both can boot with DT only.
Set the dma_data.filter_data to the DMA name which will be used by omap-pcm
to request the DMA channel.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@linaro.org>

sound/soc/omap/omap-dmic.c

@@ -57,7 +57,6 @@ struct omap_dmic {
 	struct mutex mutex;
 
 	struct snd_dmaengine_dai_dma_data dma_data;
-	unsigned int dma_req;
 };
 
 static inline void omap_dmic_write(struct omap_dmic *dmic, u16 reg, u32 val)
@@ -478,15 +477,7 @@ static int asoc_dmic_probe(struct platform_device *pdev)
 	}
 	dmic->dma_data.addr = res->start + OMAP_DMIC_DATA_REG;
 
-	res = platform_get_resource(pdev, IORESOURCE_DMA, 0);
-	if (!res) {
-		dev_err(dmic->dev, "invalid dma resource\n");
-		ret = -ENODEV;
-		goto err_put_clk;
-	}
-
-	dmic->dma_req = res->start;
-	dmic->dma_data.filter_data = &dmic->dma_req;
+	dmic->dma_data.filter_data = "up_link";
 
 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "mpu");
 	if (!res) {