arm: dts: dra7: add syscon phandle to cpsw node

There are 2 MACIDs stored in the control module of the dra7.
These are read by the cpsw driver if no valid MACID was found
in the devicetree.
Signed-off-by: Mugunthan V N <mugunthanvnm@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

arch/arm/boot/dts/dra7.dtsi

@@ -1447,6 +1447,7 @@ mac: ethernet@4a100000 {
 				     <GIC_SPI 336 IRQ_TYPE_LEVEL_HIGH>,
 				     <GIC_SPI 337 IRQ_TYPE_LEVEL_HIGH>;
 			ranges;
+			syscon = <&scm_conf>;
 			status = "disabled";
 
 			davinci_mdio: mdio@48485000 {