MIPS: Add missing calls to plat_unmap_dma_mem.

dma_free_noncoherent() and dma_free_coherent() are missing calls to
plat_unmap_dma_mem().  This patch adds them.
Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/mm/dma-default.c

@@ -111,6 +111,7 @@ EXPORT_SYMBOL(dma_alloc_coherent);
 void dma_free_noncoherent(struct device *dev, size_t size, void *vaddr,
 	dma_addr_t dma_handle)
 {
+	plat_unmap_dma_mem(dma_handle);
 	free_pages((unsigned long) vaddr, get_order(size));
 }
 
@@ -121,6 +122,8 @@ void dma_free_coherent(struct device *dev, size_t size, void *vaddr,
 {
 	unsigned long addr = (unsigned long) vaddr;
 
+	plat_unmap_dma_mem(dma_handle);
+
 	if (!plat_device_is_coherent(dev))
 		addr = CAC_ADDR(addr);