ARM: zynq: DT: Remove bogus value from 'bias-disable' property

In one pinctrl node, a 'bias-disable' property is erroneously assigned a
value.

Fixes: ARM: zynq: DT: Add pinctrl information
Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Reviewed-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>

arch/arm/boot/dts/zynq-zc702.dts

@@ -309,7 +309,7 @@ conf-rx {
 
 		conf-tx {
 			pins = "MIO48";
-			bias-disable = <0>;
+			bias-disable;
 		};
 	};
 };