[SPARK-20605][CORE][YARN][MESOS] Deprecate not used AM and executor port configuration

## What changes were proposed in this pull request?

After SPARK-10997, client mode Netty RpcEnv doesn't require to start server, so port configurations are not used any more, here propose to remove these two configurations: "spark.executor.port" and "spark.am.port".

## How was this patch tested?

Existing UTs.

Author: jerryshao <sshao@hortonworks.com>

Closes #17866 from jerryshao/SPARK-20605.