How to enable 1536MHz for OrangePi PC?

[human890209]

OrangePi PC said it could run up to 1.6GHz.
I build a kernel 4.1x Desktop for my OrangePi PC. But the max CPU frequency is 1.296GHz. I got my OPI PC a sink and fan. I think maybe it's a general build for all the H3 board, I see some H3 board's CPU frequency is 1.2GHz, but I want my PC model to hit a higher frequency.
I check the scailing_available_frequency, the max frequency is 1296000.

How to add 1344000, 1440000, 1536000 into the available frequency list?
Should I add those to the sun8i_h3.dtsi file? Any other file should be modified?
I'm new to Linux, start from my newly received OrangePi PC, hope you could answer in details.