fsl_dma: Fix Channel Start bug in dma_check()

The Channel Start (CS) bit in the Mode Register (MR) should actually be
cleared as the comment in the code suggests.  Previously, CS was being
set, not cleared.

Assuming normal operation of the DMA engine, this change shouldn't have
any real affect.
Signed-off-by: NPeter Tyser <ptyser@xes-inc.com>
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>

drivers/dma/fsl_dma.c

@@ -60,7 +60,7 @@ static uint dma_check(void) {
 	} while (status & FSL_DMA_SR_CB);
 
 	/* clear MR[CS] channel start bit */
-	out_be32(&dma->mr, in_be32(&dma->mr) & FSL_DMA_MR_CS);
+	out_be32(&dma->mr, in_be32(&dma->mr) & ~FSL_DMA_MR_CS);
 	dma_sync();
 
 	if (status != 0)