retain_cpu_freq: Track governor

Governor is set to Cpu0's setting by default upon resume,
remove dependency from each individual core and allow unique.
Add initial CPU-boost hooks

CPU is currently boosted for these activities:
*Starting video playback (1350MHz for 5s)
*Recording video (594MHz indefinite)
*Turning on the display (1188MHz for 7s)
Boost max freq to 1890MHz