Thermal: Provide option to choose default thermal governor

This patch provides option to choose the default thermal
governor. If no option is provided, the step_wise
governor is selected by default.
Signed-off-by: NDurgadoss R <durgadoss.r@intel.com>
Signed-off-by: NZhang Rui <rui.zhang@intel.com>

drivers/thermal/Kconfig

@@ -73,3 +73,34 @@ config USER_SPACE
 	depends on THERMAL
 	help
 	  Enable this to let the user space manage the platform thermals.
+
+choice
+	prompt "Default Thermal governor"
+	depends on THERMAL
+	default THERMAL_DEFAULT_GOV_STEP_WISE
+	help
+	  This option sets which thermal governor shall be loaded at
+	  startup. If in doubt, select 'step_wise'.
+
+config THERMAL_DEFAULT_GOV_STEP_WISE
+	bool "step_wise"
+	select STEP_WISE
+	help
+	  Use the step_wise governor as default. This throttles the
+	  devices one step at a time.
+
+config THERMAL_DEFAULT_GOV_FAIR_SHARE
+	bool "fair_share"
+	select FAIR_SHARE
+	help
+	  Use the fair_share governor as default. This throttles the
+	  devices based on their 'contribution' to a zone. The
+	  contribution should be provided through platform data.
+
+config THERMAL_DEFAULT_GOV_USER_SPACE
+	bool "user_space"
+	select USER_SPACE
+	help
+	  Select this if you want to let the user space manage the
+	  platform thermals.
+endchoice