net: ethernet: ti: am65-cpsw-ethtool: use pm_runtime_resume_and_get

Using pm_runtime_resume_and_get() to replace pm_runtime_get_sync and
pm_runtime_put_noidle. This change is just to simplify the code, no
actual functional changes.

Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Minghao Chi <chi.minghao@zte.com.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>