[feat] add cvi_update_rtos tool [feat](uboot):Support uart download Change-Id: I4027f9ceba4205d2d5c7c5135b888172ac49203a
1. add cvitek folders to u-boot-2021.10 2. add cv183x/cv182x part 3. add cv181x/cv180x part Change-Id: I6dc2e5ff509dbab16bd60bfb3fd61852da5e01f6