Reboot property to control system reboot on PPC4xx systems:

By setting "reset_type" to one of the following values, the default
software reset mechanism may be overridden. Here the possible values of
"reset_type":

      1 - PPC4xx core reset
      2 - PPC4xx chip reset
      3 - PPC4xx system reset (default)

Example:

		cpu@0 {
			device_type = "cpu";
			model = "PowerPC,440SPe";
			...
			reset-type = <2>;	/* Use chip-reset */
		};
