[mips][msa] Update format of RUN lines for every MSA MC test.

1. The arch directive now appears before the cpu directive
2. Long run lines were split across multiple lines
    
No functional changes.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@197588 91177308-0d34-0410-b5e6-96231b3b80d8