clk: rmobile: Add RCar Gen3 clock driver

Add clock driver for the RCar Gen3 R8A7795 and R8A7796 SoCs .
This driver allows reading out the clock configuration set by
previous boot stages and enabling and disabling clock using
the MSTP registers. Setting clock is not supported thus far.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
Signed-off-by: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
index 44da716..60bd706 100644
--- a/drivers/clk/Kconfig
+++ b/drivers/clk/Kconfig
@@ -55,5 +55,6 @@
 source "drivers/clk/uniphier/Kconfig"
 source "drivers/clk/exynos/Kconfig"
 source "drivers/clk/at91/Kconfig"
+source "drivers/clk/renesas/Kconfig"
 
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