arm64: Enable the timer on Rockchip architecture

On the RK3368 SoC, support the APB timers for rockchip platform.
Signed-off-by: Caesar Wang <wxt@rock-chips.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>

arch/arm64/Kconfig.platforms

@@ -60,6 +60,7 @@ config ARCH_ROCKCHIP
 	select ARCH_REQUIRE_GPIOLIB
 	select PINCTRL
 	select PINCTRL_ROCKCHIP
+	select ROCKCHIP_TIMER
 	help
 	  This enables support for the ARMv8 based Rockchip chipsets,
 	  like the RK3368.