dmaengine: mmp_tdma: statify symbols

Sparse complains:

drivers/dma/mmp_tdma.c:407:22: warning: symbol 'mmp_tdma_alloc_descriptor' was not declared. Should it be static?
drivers/dma/mmp_tdma.c:595:17: warning: symbol 'mmp_tdma_xlate' was not declared. Should it be static?

Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Cc: Qiao Zhou <zhouqiao@marvell.com>
diff --git a/drivers/dma/mmp_tdma.c b/drivers/dma/mmp_tdma.c
index ba7f412..b3441f5 100644
--- a/drivers/dma/mmp_tdma.c
+++ b/drivers/dma/mmp_tdma.c
@@ -404,7 +404,7 @@
 	return;
 }
 
-struct mmp_tdma_desc *mmp_tdma_alloc_descriptor(struct mmp_tdma_chan *tdmac)
+static struct mmp_tdma_desc *mmp_tdma_alloc_descriptor(struct mmp_tdma_chan *tdmac)
 {
 	struct gen_pool *gpool;
 	int size = tdmac->desc_num * sizeof(struct mmp_tdma_desc);
@@ -592,7 +592,7 @@
 	return true;
 }
 
-struct dma_chan *mmp_tdma_xlate(struct of_phandle_args *dma_spec,
+static struct dma_chan *mmp_tdma_xlate(struct of_phandle_args *dma_spec,
 			       struct of_dma *ofdma)
 {
 	struct mmp_tdma_device *tdev = ofdma->of_dma_data;