rockchip: Add rk3568 architecture core

RK3568 is a high-performance and low power quad-core application
processor designed for personal mobile internet device and AIoT
equipments.

Signed-off-by: Joseph Chen <chenjh@rock-chips.com>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
diff --git a/arch/arm/mach-rockchip/Makefile b/arch/arm/mach-rockchip/Makefile
index 121f23a..00aef0e 100644
--- a/arch/arm/mach-rockchip/Makefile
+++ b/arch/arm/mach-rockchip/Makefile
@@ -42,6 +42,7 @@
 obj-$(CONFIG_ROCKCHIP_RK3328) += rk3328/
 obj-$(CONFIG_ROCKCHIP_RK3368) += rk3368/
 obj-$(CONFIG_ROCKCHIP_RK3399) += rk3399/
+obj-$(CONFIG_ROCKCHIP_RK3568) += rk3568/
 obj-$(CONFIG_ROCKCHIP_RV1108) += rv1108/
 
 # Clear out SPL objects, in case this is a TPL build