net: macb: Add WoL interrupt support for MACB type of Ethernet controller

Handle the Wake-on-Lan interrupt for the Cadence MACB Ethernet
controller.
As we do for the GEM version, we handle of WoL interrupt in a
specialized interrupt handler for MACB version that is positionned
just between suspend() and resume() calls.

Cc: Claudiu Beznea <claudiu.beznea@microchip.com>
Cc: Harini Katakam <harini.katakam@xilinx.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>