rockchip: rk3288: Add clock driver

Add a driver for setting up and modifying the various PLLs and peripheral
clocks on the RK3288.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
index bb89fb9..008ec10 100644
--- a/drivers/clk/Makefile
+++ b/drivers/clk/Makefile
@@ -6,4 +6,5 @@
 #
 
 obj-$(CONFIG_CLK) += clk-uclass.o
+obj-$(CONFIG_ROCKCHIP_RK3288) += clk_rk3288.o
 obj-$(CONFIG_SANDBOX) += clk_sandbox.o