[feat]: add 2D RoPE

[jpthu17]

[kabachuha]

Hi! Please consider adding it to Latte as well, because there's a plan to make it the main codebase instead of vanilla DiT

And both variants may also benefit if it's added to the OpenDiT repo as well https://github.com/NUS-HPC-AI-Lab/OpenDiT/

[kabachuha]

Another note is that if you're adding Rotary embeddings, you need to remove the sinusoidal ones, to not repeat them