[llvm] [RISCV] Xqcilb: rename JUMP_PLT fixup and drop `@plt` parsing (PR #135507)

[Sudharsan Veeravalli via llvm-commits]

svs-quic wrote:

If we are to go ahead with this change, you might want to rename the the relocation in `llvm/include/llvm/BinaryFormat/ELFRelocs/RISCV_nonstandard.def` as well.

https://github.com/llvm/llvm-project/pull/135507