powerpc: Move 32-bit probe() machine to later in the boot process

This converts all the 32-bit platforms to use the expanded device-tree
which is a pretty mechanical change. Unlike 64-bit, the 32-bit kernel
didn't rely on platform initializations to setup the MMU since it
sets it up entirely before probe_machine() so the move has comparatively
less consequences though it's a bigger patch.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/platforms/85xx/sbc8548.c

@@ -120,9 +120,7 @@ machine_arch_initcall(sbc8548, mpc85xx_common_publish_devices);
  */
 static int __init sbc8548_probe(void)
 {
-        unsigned long root = of_get_flat_dt_root();
-
-        return of_flat_dt_is_compatible(root, "SBC8548");
+	return of_machine_is_compatible("SBC8548");
 }
 
 define_machine(sbc8548) {