[display] enable display on/off handling in actdead

Signed-off-by: Pekka Lundstrom <pekka.lundstrom@jollamobile.com>
Provide visibility to cached display state polling

The transient power up/down states do not show up in datapipe
output triggers, but code that reads directly from datapipe
might see them and cause problems. These changes make it easier
to find the places where this happens.
Do not generate activity from power key events

This keeps the display from coming back on due to power key
up events.
Skip tklock activity in act dead

Make power key handler toggle between display on / off states
instead of doing tklock ipc in act dead.

Also stop tklock module from processing power key events.
Fixes to display state transitions

Allow transitions to logical off even if lipstick is not available.

If possible, initiate display state transitions directly from
request instead of going through idle callback. This makes legacy
code that expects state transitions to be immediate less likely
to misfire.

Do not modify cached display state from datapipe input filter.
Disable longer dim timeout when USER or ACT_DEAD is reached
Default to minimally light display on mce startup

Target brightness gets set when the first display state transition
finishes, meanwhile we want to use as little power as possible.
Remove unused variables
Add extra debug toggles
Merge pull request #101 from spiiroin/act_dead

Enable display on/off handling in actdead