r8152: avoid the MCU to clear the lanwake

Avoid the MCU to clear the lanwake after suspending. It may cause the
WOL fail. Disable LANWAKE_CLR_EN before suspending. Besides,enable it
and reset the lanwake status when resuming or initializing.

Signed-off-by: Hayes Wang <hayeswang@realtek.com>
Signed-off-by: David S. Miller <davem@davemloft.net>