staging: octeon: fix broken phylib usage

Commit 2b3e88ea ("net: phy: improve phy state checking")
added checks for phylib usage, and this triggers with OCTEON ethernet
and results in broken networking.

Fix by replacing phy_start_aneg() with phy_start().

Fixes: 2b3e88ea ("net: phy: improve phy state checking")
Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>