r8169: disable ASPM during NAPI poll

Several chip versions have problems with ASPM, what may result in
rx_missed errors or tx timeouts. The root cause isn't known but
experience shows that disabling ASPM during NAPI poll can avoid
these problems.

Suggested-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
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>