Delete Core-V-MCU-SoC-Plan_V1.2.pod

[jasperlin05]

It is replaced by its updated version.

[MikeOpenHWGroup]

Hi @jasperlin05. In the future, you can remove the version number from the SoC-Plan filename. The versioning information is maintained as meta-data by git automatically. So all you need is to have a file named Core-V-MCU-SoC-Plan.pod and push in updates as needed. We can always get back any specific version we want.