clk: add CS2000 Fractional-N driver

This patch adds CS2000 Fractional-N driver as clock provider.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
[sboyd@codeaurora.org: Fix unsigned checked for < 0 in
cs2000_ratio_get()]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
index c3e3a02..d2d3871 100644
--- a/drivers/clk/Kconfig
+++ b/drivers/clk/Kconfig
@@ -116,6 +116,12 @@
 	  Given a target output frequency, the driver will set the PLL and
 	  divider to best approximate the desired output.
 
+config COMMON_CLK_CS2000_CP
+	tristate "Clock driver for CS2000 Fractional-N Clock Synthesizer & Clock Multiplier"
+	depends on I2C
+	help
+	  If you say yes here you get support for the CS2000 clock multiplier.
+
 config COMMON_CLK_S2MPS11
 	tristate "Clock driver for S2MPS1X/S5M8767 MFD"
 	depends on MFD_SEC_CORE