ARM: dts: lpc32xx: Remove unused and undocumented 'pnx,timeout'

'pnx,timeout' is unused, undocumented and 'pnx' is not a vendor prefix,
so let's remove it.
Acked-by: Vladimir Zapolskiy <vz@mleia.com>
Cc: Sylvain Lemieux <slemieux.tyco@gmail.com>
Link: https://lore.kernel.org/r/20201210175238.2721550-1-robh@kernel.orgSigned-off-by: Rob Herring <robh@kernel.org>

arch/arm/boot/dts/lpc32xx.dtsi

@@ -123,7 +123,6 @@ i2cusb: i2c@300 {
 				clocks = <&usbclk LPC32XX_USB_CLK_I2C>;
 				#address-cells = <1>;
 				#size-cells = <0>;
-				pnx,timeout = <0x64>;
 			};
 
 			usbclk: clock-controller@f00 {
@@ -286,7 +285,6 @@ i2c1: i2c@400a0000 {
 				interrupts = <19 IRQ_TYPE_LEVEL_LOW>;
 				#address-cells = <1>;
 				#size-cells = <0>;
-				pnx,timeout = <0x64>;
 				clocks = <&clk LPC32XX_CLK_I2C1>;
 			};
 
@@ -297,7 +295,6 @@ i2c2: i2c@400a8000 {
 				interrupts = <18 IRQ_TYPE_LEVEL_LOW>;
 				#address-cells = <1>;
 				#size-cells = <0>;
-				pnx,timeout = <0x64>;
 				clocks = <&clk LPC32XX_CLK_I2C2>;
 			};