musa: fix failures in test-backend-ops for mul_mat_id op (#15236) * musa: fix failures in test-backend-ops for mul_mat_id op Signed-off-by: Xiaodong Ye <[email protected]> * Address review comments Signed-off-by: Xiaodong Ye <[email protected]> --------- Signed-off-by: Xiaodong Ye <[email protected]>