dmaengine: shdma: Use defines instead of hardcoded numbers

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
diff --git a/drivers/dma/sh/shdmac.c b/drivers/dma/sh/shdmac.c
index 1a6f659..58eb857 100644
--- a/drivers/dma/sh/shdmac.c
+++ b/drivers/dma/sh/shdmac.c
@@ -239,9 +239,8 @@
 {
 	/*
 	 * Default configuration for dual address memory-memory transfer.
-	 * 0x400 represents auto-request.
 	 */
-	u32 chcr = DM_INC | SM_INC | 0x400 | log2size_to_chcr(sh_chan,
+	u32 chcr = DM_INC | SM_INC | RS_AUTO | log2size_to_chcr(sh_chan,
 						   LOG2_DEFAULT_XFER_SIZE);
 	sh_chan->xmit_shift = calc_xmit_shift(sh_chan, chcr);
 	chcr_write(sh_chan, chcr);