move: rockchip: move clock drivers into a subdirectory

With the number of Rockchip clock drivers increasing, don't clutter up
the core drivers/clk directory with them and instead move them out of
the way into a separate subdirectory.

Suggested-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Simon Glass <sjg@chromium.org>
Updated for rk3399:
Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
index e20e932..3cbdd54 100644
--- a/drivers/clk/Makefile
+++ b/drivers/clk/Makefile
@@ -6,9 +6,7 @@
 #
 
 obj-$(CONFIG_CLK) += clk-uclass.o clk_fixed_rate.o
-obj-$(CONFIG_ROCKCHIP_RK3036) += clk_rk3036.o
-obj-$(CONFIG_ROCKCHIP_RK3288) += clk_rk3288.o
-obj-$(CONFIG_ROCKCHIP_RK3399) += clk_rk3399.o
+obj-$(CONFIG_ARCH_ROCKCHIP) += rockchip/
 obj-$(CONFIG_SANDBOX) += clk_sandbox.o
 obj-$(CONFIG_SANDBOX) += clk_sandbox_test.o
 obj-$(CONFIG_MACH_PIC32) += clk_pic32.o