[regression] HDMI breakage just before poweroff

[Vicente Bergas]

Hello,
on rk3399-sapphire there is a missing feature: the poweroff command is
unable to poweroff the system and the display stays on.
When the system is halted, power needs to be removed manually.

With Linux kernel 4.16, when reaching the halted state, the HDMI console
shows the last messages before halting.

With 4.17.0-rc3, when reaching the halted state, the HDMI console
shows colorful static noise.

Regards,
  Vicente.