Add ratified Zimop extension

[ved-rivos]

Description

Provide a detailed description of the changes performed by the PR.
Adds support for Zimop extension

Related Issues

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

Ratified/Unratified Extensions

• Ratified
• [] 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-isa-manual/blob/main/src/zimop.adoc

Reference Model Used

• [X ] SAIL
• Spike
• Other - < SPECIFY HERE >

Mandatory Checklist:

• [X ] All tests are compliant with the test-format spec present in this repo ?
• [ X] Ran the new tests on RISCOF with SAIL/Spike as reference model successfully ?
• Ran the new tests on RISCOF in coverage mode
• Link to Google-Drive folder containing the new coverage reports (See this for more info): < SPECIFY HERE >
• Link to PR in RISCV-ISAC from which the reports were generated : < SPECIFY HERE >
• Changelog entry created with a minor patch

Optional Checklist:

• [ X] RISCV-V CTG PR link if tests were generated using it : Add support for unratified Zimop extension riscv-software-src/riscv-ctg#80
• Were the tests hand-written/modified ?
• [ X] Have you run these on any hard DUT model ? Please specify name and provide link if possible in the description Spike
• If you have modified arch_test.h Please provide a detailed description of the changes in the Description section above.

[allenjbaum]

We need to see the coverage report, from the checklist above, otherwise this looks good to go:

• Ran the new tests on RISCOF in coverage mode
• Link to Google-Drive folder containing the new coverage reports (See this for more info): < SPECIFY HERE >

[UmerShahidengr]

As coverpoints and tests are complete, and all of its dependent PR have been merged, so I am merging it too.