[llvm] [RISCV] Update Zfa extension version to 1.0 (PR #67964)

[Alex Bradbury via llvm-commits]

asb wrote:

> ⚠️ C/C++ code formatter, clang-format found issues in your code. ⚠️

This is a whitespace change > 20 lines away from the edit made in the test file, so I don't believe it's appropriate to reformat in this PR.

https://github.com/llvm/llvm-project/pull/67964