feat: add GammaV2 support for board 601a

[awxhw]

This PR adds complete firmware support for StarMiner bitaxeGamma601a.

1. Updated board config, power and thermal settings for V2 hardware revision.
2. Code follows the existing project structure without breaking other devices.
3. Full stability mining test finished, all core functions operate normally.
4. I will maintain this hardware port long-term and handle subsequent compatibility updates.
   Hardware repo: https://github.com/awxhw/StarMiner/tree/master/sch.