ARM: dts: meson8b: odroidc1: use the MAC address stored in the eFuse

Odroid-C1 uses the MAC address stored in eFuse at offset 0x1b4 (which is
defined as a "standard" offset for all Meson8 and Meson8b boards, but
testing shows that MXQ doesn't have the eFuse values programmed and
EC-100 stores it's MAC address in eMMC).

Add the nvmem cell which points to the MAC address and asssign it to the
Ethernet controller as "mac-address".
As result of this the MAC address which is stored in the eFuse is now
assigned to the Ethernet controller and consistent across reboots.
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Kevin Hilman <khilman@baylibre.com>

arch/arm/boot/dts/meson8b-odroidc1.dts

@@ -190,6 +190,12 @@ &cpu0 {
 	cpu-supply = <&vcck>;
 };
 
+&efuse {
+	ethernet_mac_address: mac@1b4 {
+		reg = <0x1b4 0x6>;
+	};
+};
+
 &ethmac {
 	status = "okay";
 
@@ -200,6 +206,9 @@ &ethmac {
 	phy-handle = <&eth_phy>;
 	amlogic,tx-delay-ns = <4>;
 
+	nvmem-cells = <&ethernet_mac_address>;
+	nvmem-cell-names = "mac-address";
+
 	mdio {
 		compatible = "snps,dwmac-mdio";
 		#address-cells = <1>;