MIPS: Add a platform hook for swiotlb setup.

This allows platforms that are using the swiotlb to initialize it.

Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Patchwork: http://patchwork.linux-mips.org/patch/1638/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/kernel/setup.c

@@ -490,6 +490,7 @@ static void __init arch_mem_init(char **cmdline_p)
 	bootmem_init();
 	device_tree_init();
 	sparse_init();
+	plat_swiotlb_setup();
 	paging_init();
 }