Describe how to generate and change kernel config.
Signed-off-by: Jianping Liu <frankjpliu@tencent.com>
Reviewed-by: Yongliang Gao <leonylgao@tencent.com>
Sync code to the same with tk4 pub/lts/0017-kabi, except deleted rue
and wujing. Partners can submit pull requests to this branch, and we
can pick the commits to tk4 pub/lts/0017-kabi easly.
Signed-off-by: Jianping Liu <frankjpliu@tencent.com>