ARM: rockchip: honor renaming of cpufreq-cpu0 to cpufreq-dt

cpufreq-cpu0 got renamed to a more generic name cpufreq-dt, so
adapt the created platform-device to this.
Reported-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>

arch/arm/mach-rockchip/rockchip.c

@@ -27,7 +27,7 @@
 static void __init rockchip_dt_init(void)
 {
 	of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);
-	platform_device_register_simple("cpufreq-cpu0", 0, NULL, 0);
+	platform_device_register_simple("cpufreq-dt", 0, NULL, 0);
 }
 
 static const char * const rockchip_board_dt_compat[] = {