power: Don't send obsolete DISPLAY_OFF opcode

This opcode is obsolete as perflock doesn't actually handle it.
It was originally meant for 8974, but was replaced later on.

The exact same opcode was removed for the interactive governor
a while back, so remove it for the ondemand governor as well.

Change-Id: I7bc5d6f28a827d3e8c83acde1319577db3d06ea6
1 file changed