arm64: dts: marvell: use lower case for unit address and reg property

This fixes the following DTC warning:

  <stdout>: Warning (simple_bus_reg): Node /ap806/config-space@f0000000/thermal@6f808C simple-bus unit address format error, expected "6f808c"
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>

arch/arm64/boot/dts/marvell/armada-ap806.dtsi

@@ -286,9 +286,9 @@ ap_gpio: gpio@1040 {
 				};
 			};
 
-			ap_thermal: thermal@6f808C {
+			ap_thermal: thermal@6f808c {
 				compatible = "marvell,armada-ap806-thermal";
-				reg = <0x6f808C 0x4>,
+				reg = <0x6f808c 0x4>,
 				      <0x6f8084 0x8>;
 			};
 		};