microblaze: timer: Remove unused properties

This removes properties not used by either the PWM or timer drivers.
This lets us set additionalProperties: false.

Signed-off-by: Sean Anderson <sean.anderson@seco.com>
Acked-by: Michal Simek <michal.simek@xilinx.com>
Link: https://lore.kernel.org/r/20211025180605.252476-1-sean.anderson@seco.com
Signed-off-by: Michal Simek <michal.simek@xilinx.com>

arch/microblaze/boot/dts/system.dts

@@ -347,12 +347,7 @@
 			interrupts = < 3 2 >;
 			reg = < 0x83c00000 0x10000 >;
 			xlnx,count-width = <0x20>;
-			xlnx,family = "virtex5";
-			xlnx,gen0-assert = <0x1>;
-			xlnx,gen1-assert = <0x1>;
 			xlnx,one-timer-only = <0x0>;
-			xlnx,trig0-assert = <0x1>;
-			xlnx,trig1-assert = <0x1>;
 		} ;
 	} ;
 }  ;