Add Zabha extension

[ved-rivos]

Description

Provide a detailed description of the changes performed by the PR.

Add Zabha extension

Related Issues

Please list all the issues related to this PR. Use NA if no issues exist.

Update to/for Ratified/Unratified Extensions

• Ratified
• [X ] Unratified

List Extensions

List the extensions that your PR affects. In case of unratified extensions, please provide a link to the spec draft that was referred to make this PR.

https://github.com/riscv/riscv-zabha

Mandatory Checklist:

• [X ] Make sure you have updated the versions in setup.cfg and riscv_config/__init__.py. Refer to CONTRIBUTING.rst file for further information.
• [ X] Make sure to have created a suitable entry in the CHANGELOG.md.