net: stmmac: option to enable PHY WOL with PMT enabled

The current stmmac driver WOL implementation will enable MAC WOL
if MAC HW PMT feature is on. Else, the driver will check for
PHY WOL support. There is another case where MAC HW PMT is
enabled but the platform still goes for the PHY WOL option.
E.g, Intel platform are designed for PHY WOL but not MAC WOL
although HW MAC PMT features are enabled.

Introduce use_phy_wol platform data to select PHY WOL
instead of depending on HW PMT features. Set use_phy_wol
will disable the plat->pmt which currently used to
determine the system to wake up by MAC WOL or PHY WOL.

Signed-off-by: Ling Pei Lee <pei.lee.ling@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>