The mediatek,mac-wol property is being handled backwards to what is
described in the binding: it currently enables PHY WOL when the property
is present and vice versa. Invert the driver logic so it matches the
binding description.
Fixes: fd1d62d80ebc ("net: stmmac: replace the use_phy_wol field with a flag")
Signed-off-by: Nícolas F. R. A. Prado <nfraprado@xxxxxxxxxxxxx>