igb: make ioport free

This patch makes igb driver ioport-free.
This corrects behavior in probe function so as not to request ioport
resources as long as they are not really needed.

Signed-off-by: Taku Izumi <izumi.taku@jp.fujitsu.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

drivers/net/igb/igb.h

@@ -271,6 +271,10 @@ struct igb_adapter {
 	unsigned int msi_enabled;
 
 	u32 eeprom_wol;
+
+	/* for ioport free */
+	int bars;
+	int need_ioport;
 };
 
 enum e1000_state_t {