clk: keystone: Add sci-clk driver support

In K2G, the clock handling is done through firmware executing on a
separate core. Linux kernel needs to communicate to the firmware
through TI system control interface to access any power management
related resources, including clocks.

The keystone sci-clk driver does this, by communicating to the
firmware through the TI SCI driver. The driver adds support for
registering clocks through DT, and basic required clock operations
like prepare/get_rate, etc.

Signed-off-by: Tero Kristo <t-kristo@ti.com>
[sboyd@codeaurora.org: Make ti_sci_init_clocks() static]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

drivers/clk/Kconfig

@@ -164,13 +164,6 @@ config COMMON_CLK_XGENE
 	---help---
 	  Sypport for the APM X-Gene SoC reference, PLL, and device clocks.
 
-config COMMON_CLK_KEYSTONE
-	tristate "Clock drivers for Keystone based SOCs"
-	depends on (ARCH_KEYSTONE || COMPILE_TEST) && OF
-	---help---
-          Supports clock drivers for Keystone based SOCs. These SOCs have local
-	  a power sleep control module that gate the clock to the IPs and PLLs.
-
 config COMMON_CLK_NXP
 	def_bool COMMON_CLK && (ARCH_LPC18XX || ARCH_LPC32XX)
 	select REGMAP_MMIO if ARCH_LPC32XX
@@ -219,6 +212,7 @@ config COMMON_CLK_VC5
 
 source "drivers/clk/bcm/Kconfig"
 source "drivers/clk/hisilicon/Kconfig"
+source "drivers/clk/keystone/Kconfig"
 source "drivers/clk/mediatek/Kconfig"
 source "drivers/clk/meson/Kconfig"
 source "drivers/clk/mvebu/Kconfig"