[hardware] Floating-Point Reductions

[mp-17]

This PR depends on https://github.com/pulp-platform/ara/pull/133

This PR introduces FP-reduction support to Ara.

Thanks to @xiaorui-yin for the great work and effort!

Changelog

Added

• Support for vector single-width floating-point reduction instructions: vfredusum, vfredosum, vfredmin, vfredmax
• Support for Vector widening floating-point reductions: vfwredusum, vfwredosum
• fdotproduct benchmark to evaluate dot products with reductions
• fredsum benchmark to evaluate fp-reductions
• riscv-tests for vfredusum, vfredosum, vfredmin, vfredmax, vfwredusum, vfwredosum

Changed

• Updated target -march to rv64gcv_zfh_zvfh0p1 to enable half-floats support

Checklist

• [x] Automated tests pass
• [x] Changelog updated
• [x] Code style guideline is observed
• [x] No frequency degradation