[llvm] RISCV: Don't use MCTargetOptions::ABIName in the ELF target streamer (PR #224704)

[Alexander Richardson via llvm-commits]

arichardson wrote:

I'd like to see this cleanup land but I've seen some odd interactions with LTO and inline ASM. Give me a bit of time to investigate. Currently working on some tests and cleanups for this (motivated by https://github.com/llvm/llvm-project/pull/223606)

https://github.com/llvm/llvm-project/pull/224704