libpower: tuning and cleanups

 * Tune the governor for better power usage and interactivity
 * Reset tuning parameters if governor changes
 * Cleanup

Change-Id: I56f5dcc7f15e5dfbcc38338d515fd41d04662ab1
Add patch: Fix corrupted text rendering in Trebuchet

Change-Id: I070a25ac7ab9b6d4922b69395c195643b7df2bbd
FM Radio support (part 1)

Enable FM radio in configuration and add a basic vendor library.
Audio system integration is still missing, so this does not work yet.

Change-Id: I9e1c04b4262ad525a2c3adccf1aaead684e528fd