thermal/of: Rename of-thermal.c

Core thermal framework code files should start with thermal_*.
of-thermal.c does not follow this pattern and can easily be confused
with platform driver.

Fix this by renaming it to thermal_of.c
Signed-off-by: Amit Kucheria <amit.kucheria@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/f5e233d5c5dcc7c7cb56b3448da255cb2c9ef0d1.1589199124.git.amit.kucheria@linaro.org

drivers/thermal/Makefile

@@ -9,7 +9,7 @@ thermal_sys-y			+= thermal_core.o thermal_sysfs.o \
 
 # interface to/from other layers providing sensors
 thermal_sys-$(CONFIG_THERMAL_HWMON)		+= thermal_hwmon.o
-thermal_sys-$(CONFIG_THERMAL_OF)		+= of-thermal.o
+thermal_sys-$(CONFIG_THERMAL_OF)		+= thermal_of.o
 
 # governors
 thermal_sys-$(CONFIG_THERMAL_GOV_FAIR_SHARE)	+= gov_fair_share.o