rockchip: firefly-rk3288: Enable TPL support

This patch enable TPL support for firefly-rk3288 board, which works ths
same way with other RK3288 board like Tinker, evb.

Signed-off-by: Kever Yang <kever.yang@rock-chips.com>
diff --git a/arch/arm/mach-rockchip/rk3288/Kconfig b/arch/arm/mach-rockchip/rk3288/Kconfig
index 4ebc079..afb62fc 100644
--- a/arch/arm/mach-rockchip/rk3288/Kconfig
+++ b/arch/arm/mach-rockchip/rk3288/Kconfig
@@ -67,6 +67,7 @@
 	bool "Firefly-RK3288"
 	select BOARD_LATE_INIT
 	select SPL_BOARD_INIT if SPL
+	select TPL
 	help
 	  Firefly is a RK3288-based development board with 2 USB ports,
 	  HDMI, VGA, micro-SD card, audio, WiFi  and Gigabit Ethernet, It