[RISCV] Fix typo: vmv.x.i -> vmv.v.i

Author: wangpc-pp

llvm/lib/Target/RISCV/RISCVTargetTransformInfo.cpp

@@ -1663,7 +1663,7 @@ InstructionCost RISCVTTIImpl::getStoreImmCost(Type *Ty,
     return 0;
 
   if (OpInfo.isUniform())
-    // vmv.x.i, vmv.v.x, or vfmv.v.f
+    // vmv.v.i, vmv.v.x, or vfmv.v.f
     // We ignore the cost of the scalar constant materialization to be consistent
     // with how we treat scalar constants themselves just above.
     return 1;