clk: mvebu: add Kirkwood SoC-centric clock init

This is moving core clock and clock gating init for Kirkwood to its
own file and adds a Kconfig option. Also init functions are added and
declared so they get called on of_clk_init.

Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Tested-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
diff --git a/drivers/clk/mvebu/Makefile b/drivers/clk/mvebu/Makefile
index bfc3078..97d1ab0 100644
--- a/drivers/clk/mvebu/Makefile
+++ b/drivers/clk/mvebu/Makefile
@@ -4,3 +4,4 @@
 obj-$(CONFIG_MVEBU_CLK_GATING) 	+= clk-gating-ctrl.o
 
 obj-$(CONFIG_DOVE_CLK)		+= dove.o
+obj-$(CONFIG_KIRKWOOD_CLK)	+= kirkwood.o