[AMDGPU] Avoid setting op_sel_hi bits if there is matrix_b_scale. NFCI. (#154176)

This is NFCI now as there is no matrix_b_scale without matrix_b_reuse,
but technically this condition shall be here.

Author: rampitec

llvm/lib/Target/AMDGPU/MCTargetDesc/AMDGPUMCCodeEmitter.cpp

@@ -389,6 +389,8 @@ void AMDGPUMCCodeEmitter::encodeInstruction(const MCInst &MI,
        Opcode == AMDGPU::V_ACCVGPR_WRITE_B32_vi) &&
       // Matrix B format operand reuses op_sel_hi.
       !AMDGPU::hasNamedOperand(Opcode, AMDGPU::OpName::matrix_b_fmt) &&
+      // Matrix B scale operand reuses op_sel_hi.
+      !AMDGPU::hasNamedOperand(Opcode, AMDGPU::OpName::matrix_b_scale) &&
       // Matrix B reuse operand reuses op_sel_hi.
       !AMDGPU::hasNamedOperand(Opcode, AMDGPU::OpName::matrix_b_reuse)) {
     Encoding |= getImplicitOpSelHiEncoding(Opcode);