staging: et131x: Remove ai_force_[duplex|speed] from et131x_adapter

The ai_force settings were used to set the ethernet speed and duplex manually.
This is now being done by the phy_device, so remove.

Signed-off-by: Mark Einon <mark.einon@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>