[e1000] Enable interrupts in a more UNDI compatible way

Signed-off-by: Marty Connor <mdc@etherboot.org>

src/drivers/net/e1000/e1000.c

 static void
 e1000_irq_enable ( struct e1000_adapter *adapter )
 {
-	E1000_WRITE_REG ( &adapter->hw, IMS, E1000_IMS_RXDMT0 |
-			                     E1000_IMS_RXSEQ );
+	E1000_WRITE_REG ( &adapter->hw, IMS, IMS_ENABLE_MASK );
 	E1000_WRITE_FLUSH ( &adapter->hw );
 }