mips: convert fdt pointers to opaque pointers

The architecture code does not need to access the internals of the FDT
blob directly, so make the pointers to it void * and use char arrays
for section variables.

Signed-off-by: Rob Herring <robh@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Tested-by: Grant Likely <grant.likely@linaro.org>
diff --git a/arch/mips/ralink/of.c b/arch/mips/ralink/of.c
index 0170d82..91d7060 100644
--- a/arch/mips/ralink/of.c
+++ b/arch/mips/ralink/of.c
@@ -28,7 +28,7 @@
 __iomem void *rt_sysc_membase;
 __iomem void *rt_memc_membase;
 
-extern struct boot_param_header __dtb_start;
+extern char __dtb_start[];
 
 __iomem void *plat_of_remap_node(const char *node)
 {
@@ -63,7 +63,7 @@
 	 * Load the builtin devicetree. This causes the chosen node to be
 	 * parsed resulting in our memory appearing
 	 */
-	__dt_setup_arch(&__dtb_start);
+	__dt_setup_arch(__dtb_start);
 
 	if (soc_info.mem_size)
 		add_memory_region(soc_info.mem_base, soc_info.mem_size * SZ_1M,