powerpc/dts: Use 'atmel' as at24 manufacturer for pdm360ng

Using 'at' as the <manufacturer> part of the compatible string is now
deprecated. Use a correct string: 'atmel,<model>'.
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/boot/dts/pdm360ng.dts

@@ -98,7 +98,7 @@ i2c@1700 {
 			fsl,preserve-clocking;
 
 			eeprom@50 {
-				compatible = "at,24c01";
+				compatible = "atmel,24c01";
 				reg = <0x50>;
 			};