r8169: remove ASPM restrictions now that ASPM is disabled during NAPI poll

Now that  ASPM is disabled during NAPI poll, we can remove all ASPM
restrictions. This allows for higher power savings if the network
isn't fully loaded.

Reviewed-by: Simon Horman <simon.horman@corigine.com>
Tested-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com>
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>