OPAL_CEC_POWER_DOWN
===================
::

   #define OPAL_CEC_POWER_DOWN			5

   int64 opal_cec_power_down(uint64 request)

Arguments
---------
::

   uint64 request values as follows:
    0 - Power down normally
    1 - Power down immediately

This OPAL call requests OPAL to power down the system. The exact difference
between a normal and immediate shutdown is platform specific.

Current Linux kernels just use power down normally (0). It is valid for a
platform to only support some types of power down operations.

Return Values
-------------

``OPAL_SUCCESS``
  the power down was updated successful

``OPAL_BUSY``
  unable to power down, try again later

``OPAL_PARAMETER``
  a parameter was incorrect

``OPAL_INTERNAL_ERROR``
  hal code sent incorrect data to hardware device

``OPAL_UNSUPPORTED``
  this platform does not support being powered off.
