Read current values when enabling ALS/PS

When starting ALS/PS, also query the current value.

Also handle the start/stop sensor requests asynchronously without
waiting for replies.

[mce] Read current values when enabling ALS/PS
Fix display brightness pipe initialization

Set the initial value to default brightness.

Drive the config value through the brightness pipe during mce startup.
Brightness filtering module supports sensorfw only

Since we are now using ALS via sensorfw, we can drop legacy code
that operates more directly on various pieces ALS hardware.

Uses LUX->brightness tables defined in ini files instead of
hard coding within mce.

Drops support for color profiles. Skeleton functionality kept
so that external interfaces do not change.

[mce] Brightness filtering module supports sensorfw only
Add default brightness adjustment configuration file
Remove dead code
Merge pull request #74 from spiiroin/als_handling

Fixes to ALS based display brightness adjustment