[llvm] [RISCV] Use RISCV::RVVBitsPerBlock instead of 64 in getLMUL1VT. NFC (PR #144401)

[Philip Reames via llvm-commits]

https://github.com/preames approved this pull request.

LGTM - Also, I'm going to submit a change to consolidate those two.  I'd really meant to do that before landing the reverse costing change, but forgot.  

https://github.com/llvm/llvm-project/pull/144401