arch/hexagon/kernel/dma.c: make function static

This function is only used in the same file, and the other similar
functions in this file are also static.
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
[rkuo@codeaurora.org: adjusted patch to apply to latest]
Signed-off-by: Richard Kuo <rkuo@codeaurora.org>

arch/hexagon/kernel/dma.c

@@ -54,7 +54,7 @@ static struct gen_pool *coherent_pool;
 
 /* Allocates from a pool of uncached memory that was reserved at boot time */
 
-void *hexagon_dma_alloc_coherent(struct device *dev, size_t size,
+static void *hexagon_dma_alloc_coherent(struct device *dev, size_t size,
 				 dma_addr_t *dma_addr, gfp_t flag,
 				 struct dma_attrs *attrs)
 {