MIPS: OCTEON: setup: include asm/prom.h

Include arm/prom.h to get the declaration of device_tree_init().
Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/21202/
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: linux-mips@linux-mips.org

arch/mips/cavium-octeon/setup.c

@@ -38,6 +38,7 @@
 #include <asm/sections.h>
 #include <asm/fw/fw.h>
 #include <asm/setup.h>
+#include <asm/prom.h>
 #include <asm/time.h>
 
 #include <asm/octeon/octeon.h>