Use OF_getencprop to read a property, it already handles the endian

conversion so we don't need to pass the data through fdt32_to_cpu.

sys/arm/arm/generic_timer.c

@@ -361,11 +361,8 @@ arm_tmr_attach(device_t dev)
 	/* Get the base clock frequency */
 	node = ofw_bus_get_node(dev);
 	if (node > 0) {
-		error = OF_getprop(node, "clock-frequency", &clock,
+		error = OF_getencprop(node, "clock-frequency", &clock,
 		    sizeof(clock));
-		if (error > 0) {
-			sc->clkfreq = fdt32_to_cpu(clock);
-		}
 	}
 #endif