[RFC][Tracking Issue] CSI-NN2 Integration

[alter-xp]

This issue to track upstreaming progress for CSI-NN2 integration.

[RFC] RFC-CSI-NN2-Integration

• P1. The CI environment support. [CI Image] support CSI-NN2 in ci_qemu #11689
• P2. The backend with CSI-NN2 support and unit test for Conv2D.[BYOC] Integrate CSI-NN2 and add unit test for Conv2D #12526
• p3. More ops. Softmax, Pooling, Relu, and Dense.