message: compile with opt-level=z for mips target
  ref
diff: @@ -32,3 +32,10 @@ rustflags = [
  # "-C", "target-cpu=native",
  "-C", "target-feature=+aes,+crypto,+neon",
  ]
  +
  +# NOTE:
  +# mips are commonly used in routers, so binary size is more important than speed
  +[target.'cfg(target_arch = "mips")']
  +rustflags = [
  + "-C", "opt-level=z"
  +]
  