dmaengine: sf-pdma: move macro to header file

The place where the macro, SF_PDMA_REG_BASE(), is cause kernel-doc
using wrong function declaration. Move it to header file.
Signed-off-by: Green Wan <green.wan@sifive.com>
Link: https://lore.kernel.org/r/20191118143554.16129-2-green.wan@sifive.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

drivers/dma/sf-pdma/sf-pdma.c

@@ -435,7 +435,6 @@ static int sf_pdma_irq_init(struct platform_device *pdev, struct sf_pdma *pdma)
  *
  * Return: none
  */
-#define SF_PDMA_REG_BASE(ch)	(pdma->membase + (PDMA_CHAN_OFFSET * (ch)))
 static void sf_pdma_setup_chans(struct sf_pdma *pdma)
 {
 	int i;

drivers/dma/sf-pdma/sf-pdma.h

@@ -57,6 +57,8 @@
 /* Error Recovery */
 #define MAX_RETRY					1
 
+#define SF_PDMA_REG_BASE(ch)	(pdma->membase + (PDMA_CHAN_OFFSET * (ch)))
+
 struct pdma_regs {
 	/* read-write regs */
 	void __iomem *ctrl;		/* 4 bytes */