Power management fixes for 4.20-rc4

 - Fix tasks freezer deadlock in de_thread() that occurs if one
   of its sub-threads has been frozen already (Chanho Min).

 - Avoid registering a platform device by the ti-cpufreq driver
   on platforms that cannot use it (Dave Gerlach).

 - Fix a mistake in the ti-opp-supply operating performance points
   (OPP) driver that caused an incorrect reference voltage to be
   used and make it adjust the minimum voltage dynamically to avoid
   hangs or crashes in some cases (Keerthy).

 - Fix issues related to compiler flags in the cpupower utility
   and correct a linking problem in it by renaming a file with
   a duplicate name (Jiri Olsa, Konstantin Khlebnikov).
Merge branches 'pm-cpufreq' and 'pm-sleep'

* pm-cpufreq:
  cpufreq: ti-cpufreq: Only register platform_device when supported

* pm-sleep:
  exec: make de_thread() freezable