arm64: xilinx: Use lower case for partition address

Lower case should be used for register address.
Issue is reported as:
flash@0: partitions: Unevaluated properties are not allowed
('partition@22A0000' was unexpected)

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Michal Simek <michal.simek@amd.com>
Link: https://lore.kernel.org/r/a96ac9a32a363b04958157548f290d480c21590c.1695040866.git.michal.simek@amd.com

arch/arm64/boot/dts/xilinx/zynqmp-sm-k26-revA.dts

@@ -222,9 +222,9 @@
 				label = "Secure OS Storage";
 				reg = <0x2280000 0x20000>; /* 128KB */
 			};
-			partition@22A0000 {
+			partition@22a0000 {
 				label = "User";
-				reg = <0x22A0000 0x1d60000>; /* 29.375 MB */
+				reg = <0x22a0000 0x1d60000>; /* 29.375 MB */
 			};
 		};
 	};