[POWERPC] 83xx: Fix compiler warnings on 836x and 832x

Some prototypes are separated from of_device.h into of_platform.h.  Add
the new include to fix warning.
Signed-off-by: Li Yang <leoli@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

arch/powerpc/platforms/83xx/mpc832x_mds.c

@@ -25,6 +25,7 @@
 #include <linux/initrd.h>
 
 #include <asm/of_device.h>
+#include <asm/of_platform.h>
 #include <asm/system.h>
 #include <asm/atomic.h>
 #include <asm/time.h>

arch/powerpc/platforms/83xx/mpc8360e_pb.c

@@ -31,6 +31,7 @@
 #include <linux/initrd.h>
 
 #include <asm/of_device.h>
+#include <asm/of_platform.h>
 #include <asm/system.h>
 #include <asm/atomic.h>
 #include <asm/time.h>