r8169: increase the delay parameter of pm_schedule_suspend

The link down would occur when reseting PHY. And it would take about 2 ~ 5 seconds
from link down to link up. If the delay of pm_schedule_suspend is not long enough,
the device would enter runtime_suspend before link up. After link up, the device
would wake up and reset PHY again. Then, you would find the driver keep in a loop
of runtime_suspend and rumtime_resume.

Signed-off-by: Hayes Wang <hayeswang@realtek.com>
Acked-by: Francois Romieu <romieu@fr.zoreil.com>
Signed-off-by: David S. Miller <davem@davemloft.net>