rockchip: not depends on TPL_BUILD for rk3188 makefile including

The rk3188/Makefile already depends on !TPL_BUILD, so no need to add
this again in parent Makefile, remove it.

Signed-off-by: Kever Yang <kever.yang@rock-chips.com>
diff --git a/arch/arm/mach-rockchip/Makefile b/arch/arm/mach-rockchip/Makefile
index 207f900..616dd8f 100644
--- a/arch/arm/mach-rockchip/Makefile
+++ b/arch/arm/mach-rockchip/Makefile
@@ -31,9 +31,7 @@
 
 obj-$(CONFIG_ROCKCHIP_RK3036) += rk3036/
 obj-$(CONFIG_ROCKCHIP_RK3128) += rk3128/
-ifndef CONFIG_TPL_BUILD
 obj-$(CONFIG_ROCKCHIP_RK3188) += rk3188/
-endif
 obj-$(CONFIG_ROCKCHIP_RK322X) += rk322x/
 obj-$(CONFIG_ROCKCHIP_RK3288) += rk3288/
 obj-$(CONFIG_ROCKCHIP_RK3328) += rk3328/