power: Enable QCOM hardreboot implementation

* Use Qualcomm's reboot implementation.
  The rationale for this is that this is not dependent on writing
  to the param partition (as did Samsung's implementation) which means
  selinux enforcing mode will not affect writing to param, and thus
  reboot (due to failure to set reboot reason).

  This also removes the dependency on the hackish sec_param driver code
  from Samsung which relies on accessing files in userspace and is
  easily broken by file access control policies like selinux or even
  just normal unix file permissions.

 Date:      Tue May 16 14:12:24 2017 -0400
 interactive rebase in progress; onto 0d64e1f8
    pick 65d6e201816f power: Enable QCOM hardreboot implementation
    squash 1dc8206c7df3 power: Try to fix qcom hardreboot download mode