ipq806x: convert remaining mtd-mac-address-increment

Commit d284e6ef ("treewide: convert mtd-mac-address-increment* to
generic implementation") renamed "mtd-mac-address-increment" property
to "mac-address-increment". Convert remaining usages that have been
added after that.

Fixes: f44e9334 ("ipq806x: provide WiFI mac-addresses from dts")
Signed-off-by: Sungbo Eo <mans0n@gorani.run>

target/linux/ipq806x/files/arch/arm/boot/dts/qcom-ipq8064-vr2600v.dts

@@ -297,7 +297,7 @@
 
 			nvmem-cells = <&macaddr_defaultmac_0>;
 			nvmem-cell-names = "mac-address";
-			mtd-mac-address-increment = <(-1)>;
+			mac-address-increment = <(-1)>;
 		};
 	};
 };