DMA: shdma: add cyclic transfer support

This patch add cyclic transfer support and enables dmaengine_prep_dma_cyclic()

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
[reflown changelog for readablity]
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
diff --git a/include/linux/shdma-base.h b/include/linux/shdma-base.h
index f92c0a4..abdf1f2 100644
--- a/include/linux/shdma-base.h
+++ b/include/linux/shdma-base.h
@@ -54,6 +54,7 @@
 	dma_cookie_t cookie;
 	int chunks;
 	int mark;
+	bool cyclic;			/* used as cyclic transfer */
 };
 
 struct shdma_chan {