arm: rockchip: Add RK3308 SOC support

RK3308 is a quad Cortex A35 based SOC with rich audio
interfaces(I2S/PCM/TDM/PDM/SPDIF/VAD/HDMI ARC), which
designed for intelligent voice interaction and audio
input/output processing.

Signed-off-by: Andy Yan <andy.yan@rock-chips.com>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
diff --git a/arch/arm/mach-rockchip/rk3308/Makefile b/arch/arm/mach-rockchip/rk3308/Makefile
new file mode 100644
index 0000000..ce4d44b
--- /dev/null
+++ b/arch/arm/mach-rockchip/rk3308/Makefile
@@ -0,0 +1,9 @@
+#
+# (C) Copyright 2018 Rockchip Electronics Co., Ltd.
+#
+# SPDX-License-Identifier:     GPL-2.0+
+#
+
+obj-y += syscon_rk3308.o
+obj-y += rk3308.o
+obj-y += clk_rk3308.o