Enable 1080p120 TMDS rates on sunxi dw-hdmi

[raphaelscholle]

To run higher then 1080p 60fps we need to increase the TMDS clock.

• raise the TMDS clock validation limit for the Allwinner A83T dw-hdmi bridge so high-refresh CTA modes are accepted
• extend the H6 HDMI PHY MPLL table with a 297 MHz entry to lock 1080p120 TMDS rates

[RadxaYuntian]

https://discord.com/channels/855634073376260096/1412265960026669096/1437432169759903764

[RadxaStephen]

Thanks for your work.
Close it as we don't maintain boards based on H6.