dmaengine: ste_dma40: Cleanup scatterlist layering violations

This dma engine driver directly accesses page_link assuming knowledge
that should be contained only in scatterlist.h.

We replace this access with a call to sg_chain which is equivalent.
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Stephen Bates <sbates@raithlin.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Vinod Koul <vinod.koul@intel.com>
Cc: Per Förlin <per.forlin@axis.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

drivers/dma/ste_dma40.c

@@ -2528,10 +2528,7 @@ dma40_prep_dma_cyclic(struct dma_chan *chan, dma_addr_t dma_addr,
 		dma_addr += period_len;
 	}
 
-	sg[periods].offset = 0;
-	sg_dma_len(&sg[periods]) = 0;
-	sg[periods].page_link =
-		((unsigned long)sg | 0x01) & ~0x02;
+	sg_chain(sg, periods + 1, sg);
 
 	txd = d40_prep_sg(chan, sg, sg, periods, direction,
 			  DMA_PREP_INTERRUPT);