dma/ep93xx_dma.c: local symbols should be static

The symbol 'ep93xx_dma_prep_dma_memcpy' is only used in this driver
and should be marked static.
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Mika Westerberg <mika.westerberg@iki.fi>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Vinod Koul <vinod.koul@intel.com>
Acked-by: Mika Westerberg <mika.westerberg@iki.fi>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

drivers/dma/ep93xx_dma.c

@@ -902,7 +902,7 @@ static void ep93xx_dma_free_chan_resources(struct dma_chan *chan)
  *
  * Returns a valid DMA descriptor or %NULL in case of failure.
  */
-struct dma_async_tx_descriptor *
+static struct dma_async_tx_descriptor *
 ep93xx_dma_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest,
 			   dma_addr_t src, size_t len, unsigned long flags)
 {