staging: octeon-ethernet: xaui: don't register poll function in init

Link status poll function is already controlled by open/stop functions,
so we don't need to do it on init.

This eliminates a redundant xaui link status notification when the module
is loaded.

Signed-off-by: Aaro Koskinen <aaro.koskinen@nokia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>