r8152: restore hw settings

There is a capability which let the hw could change the settings
automatically when the power change to ON. However, the USB reset
would reset the settings to the hw default, so the driver has to
restore the relative settings. Otherwise, it would influence the
functions of the hw, and the compatibility for the USB hub and
USB host controller.

The relative settings are as following.
 - set the power down scale to 96.
 - enable the power saving function of USB 2.0.
 - disable the ALDPS of ECM mode.
 - set burst mode depending on the burst size.
 - enable the flow control of endpoint full.
 - set fifo empty boundary to 32448 bytes.
 - enable the function of exiting LPM when Rx OK occurs.
 - set the connect timer to 1.

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