ath79: mtd-cal-data removals

Replacement can be done with nvmem.

Signed-off-by: Rosen Penev <rosenp@gmail.com>

target/linux/ath79/dts/qca9563_compex_wpj563.dts

@@ -97,10 +97,20 @@
 				reg = <0x030000 0xfc0000>;
 			};
 
-			art: partition@ff0000 {
+			partition@ff0000 {
 				label = "art";
 				reg = <0xff0000 0x010000>;
 				read-only;
+
+				nvmem-layout {
+					compatible = "fixed-layout";
+					#address-cells = <1>;
+					#size-cells = <1>;
+
+					cal_art_1000: calibration@1000 {
+						reg = <0x1000 0x440>;
+					};
+				};
 			};
 		};
 	};
@@ -151,5 +161,6 @@
 &wmac {
 	status = "okay";
 
-	mtd-cal-data = <&art 0x1000>;
+	nvmem-cells = <&cal_art_1000>;
+	nvmem-cell-names = "calibration";
 };