r8169: improve runtime pm in rtl8169_check_link_status

This patch partially reverts commit e4fbce74 "r8169: Fix runtime
power management" from 2010. At that time the suspend delay was 100ms
and therefore suspending happened during initial aneg. Currently
suspend delay is 5s, so suspend starts after aneg and the issue
doesn't exist any longer. On my system aneg takes almost 3s, to be on
the safe side let's increase the suspend delay to 10s.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>