staging: rtl8192e: Rename PHY_RF8256_Config

Use naming schema found in other rtlwifi devices.
Rename PHY_RF8256_Config to rtl92e_config_rf.

Signed-off-by: Mateusz Kulikowski <mateusz.kulikowski@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
