powerpc/512x: initialize clocks before bus probing

Early driver probing can fail due to not available clocks
(clk_get() fails) since the clk API init didn't take place yet.
Move clocks init before bus probing.

Signed-off-by: Anatolij Gustschin <agust@denx.de>

arch/powerpc/platforms/512x/mpc512x_shared.c

@@ -431,8 +431,8 @@ void __init mpc512x_psc_fifo_init(void)
 
 void __init mpc512x_init(void)
 {
-	mpc512x_declare_of_platform_devices();
 	mpc5121_clk_init();
+	mpc512x_declare_of_platform_devices();
 	mpc512x_restart_init();
 	mpc512x_psc_fifo_init();
 }