Tahansb800bc: platform: change the platform name as tahansb800bc

[CliffyWong]

Pre-submission checklist

• I've ran the linters locally and fixed lint errors related to the files I modified in this PR. You can install the linters by running pip install -r requirements-dev.txt && pre-commit install
• pre-commit run

Summary

This PR is about updating the platform name from tahansb to tahansb800bc

Motivation

As required for the platform name update to tahansb800bc, the following modifications should be included:

1. Updated the platform and PM unit name to TAHANSB800BC in platform configurations.
2. Updated the platform name in the BSP platform mapping.
3. Updated the platform name in the general platform mapping.

Test Plan

1.Used clang and jq command to pretty the format
2.Compilation and config validation have passed
3.Bsp mapping json file could be generated succesfully
4.Platform services(platform_mananger/sensor_service/data_corral_service/fan_service/weutil/fwutil) and qsfp_service could be launched successfully.

pls refer the full logs:
PM Services&QSFP Service.zip

5.Hardware tests of platform_manager/sensor_service/data_corral_service/fan_service/weutil/fwutil passed, pls refer the logs:
PM Services HwTests.zip

logs of push f8609ae:
20251110 PM&QSFP.zip

[meta-codesync]

@ezeob002 has imported this pull request. If you are a Meta employee, you can view this in D86722417.

[meta-codesync]

@ezeob002 merged this pull request in 73c3fdd.