drivers/thermal/Makefile refactor

Signed-off-by: Zhang Rui <rui.zhang@intel.com>

drivers/thermal/Makefile

@@ -3,10 +3,16 @@
 #
 
 obj-$(CONFIG_THERMAL)		+= thermal_sys.o
-obj-$(CONFIG_CPU_THERMAL)		+= cpu_cooling.o
-obj-$(CONFIG_SPEAR_THERMAL)		+= spear_thermal.o
+
+# governors
+obj-$(CONFIG_FAIR_SHARE)	+= fair_share.o
+obj-$(CONFIG_STEP_WISE)		+= step_wise.o
+obj-$(CONFIG_USER_SPACE)	+= user_space.o
+
+# cpufreq cooling
+obj-$(CONFIG_CPU_THERMAL)	+= cpu_cooling.o
+
+# platform thermal drivers
+obj-$(CONFIG_SPEAR_THERMAL)	+= spear_thermal.o
 obj-$(CONFIG_RCAR_THERMAL)	+= rcar_thermal.o
-obj-$(CONFIG_EXYNOS_THERMAL)		+= exynos_thermal.o
-obj-$(CONFIG_FAIR_SHARE)		+= fair_share.o
-obj-$(CONFIG_STEP_WISE)			+= step_wise.o
-obj-$(CONFIG_USER_SPACE)		+= user_space.o
+obj-$(CONFIG_EXYNOS_THERMAL)	+= exynos_thermal.o