RK3399's: Add multimedia and OC overlays
We are adding the following overlays for both RK3399 kernels:
RPi Camera v1 (OV5647)
RPi Camera v2 (IMX219)
RPi 7-inch touchscreen
CPU overclocking to 2.0/1.5 GHz
CPU overclocking to 2.2/1.7 GHz
In the case of the RK3399 kernel, the overlays replace the previous opp patches, which were not effective because FriendlyARM's kernel uses ASV to limit maximum frequency. The overlays take care of re-adjusting ASV too when enabled.
OC stability has been intensively tested for both levels in my NanoPC-T4 and Rockpi.4b. They proved to be completely stable, though the faster one requires active cooling or throttling will happen very soon.