dmaengine: imx-sdma: remove IMX_DMA_SG_LOOP handling in sdma_prep_slave_sg()

This is a leftover from the time that the driver did not have
sdma_prep_dma_cyclic callback and implemented sound dma as a looped
sg chain.  And it can be removed now.
Signed-off-by: NShawn Guo <shawn.guo@freescale.com>
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>

drivers/dma/imx-sdma.c

@@ -931,12 +931,6 @@ static struct dma_async_tx_descriptor *sdma_prep_slave_sg(
 
 		param = BD_DONE | BD_EXTD | BD_CONT;
 
-		if (sdmac->flags & IMX_DMA_SG_LOOP) {
-			param |= BD_INTR;
-			if (i + 1 == sg_len)
-				param |= BD_WRAP;
-		}
-
 		if (i + 1 == sg_len)
 			param |= BD_INTR;