pch_gbe dreiver: chang author

This driver's AUTHOR was changed to "Toshiharu Okada" from "Masayuki Ohtake".
I update the Kconfig, renamed "Topcliff" to "EG20T".

Signed-off-by: Toshiharu Okada <toshiharu-linux@dsn.okisemi.com>
Signed-off-by: David S. Miller <davem@davemloft.net>