ARM: at91/dt: at91-ariag25: remove useless adc properties

Remove the properties that are not used anymore by the at91_adc driver.

Signed-off-by: Alexandre Belloni <[e-mail]>
Cc: Douglas Gilbert <[e-mail]>
Signed-off-by: Nicolas Ferre <[e-mail]>

arch/arm/boot/dts/at91-ariag25.dts

···
 			adc0: adc@f804c000 {
 				status = "okay";
 				atmel,adc-channels-used = <0xf>;
-				atmel,adc-num-channels = <4>;
 			};
 
 			dbgu: serial@fffff200 {