MAINTAINERS: xgene: Add driver and documentation path

Added path to the MDIO driver and Documentation file.
Signed-off-by: NIyappan Subramanian <isubramanian@apm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

MAINTAINERS

@@ -839,7 +839,9 @@ M:	Iyappan Subramanian <isubramanian@apm.com>
 M:	Keyur Chudgar <kchudgar@apm.com>
 S:	Supported
 F:	drivers/net/ethernet/apm/xgene/
+F:	drivers/net/phy/mdio-xgene.c
 F:	Documentation/devicetree/bindings/net/apm-xgene-enet.txt
+F:	Documentation/devicetree/bindings/net/apm-xgene-mdio.txt
 
 APTINA CAMERA SENSOR PLL
 M:	Laurent Pinchart <Laurent.pinchart@ideasonboard.com>