net: dsa: qca8k: empty qca8k_get_eee

phy_ethtool_get_eee is already called by the DSA layer, thus remove the
duplicated call in the qca8k driver.

Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>