Fix cmake build errors for Linux (#17581)

When trying to build TensorFlow with cmake for Linux, as
was specified:
```
tensorflow/tools/ci_build/ci_build.sh CMAKE tensorflow/tools/ci_build/builds/cmake.sh
```

The following error encountered:
```
grpc/src/grpc/libgrpc_unsecure.a(grpc_ares_wrapper.cc.o): In function `on_txt_done_cb(void*, int, int, unsigned char*, int)':
grpc_ares_wrapper.cc:(.text+0x256): undefined reference to `ares_parse_txt_reply_ext'
grpc_ares_wrapper.cc:(.text+0x267): undefined reference to `ares_strerror'
grpc_ares_wrapper.cc:(.text+0x363): undefined reference to `ares_free_data'
```

This fix fixes the above issue with libcares.a in cmake file.

Signed-off-by: Yong Tang <yong.tang.github@outlook.com>