thermal: re-name thermal.c to thermal_sys.c

thermal_sys was already the name of the resulting module,
and it is built from  this one source file.

Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile
index 02b64517..31108a0 100644
--- a/drivers/thermal/Makefile
+++ b/drivers/thermal/Makefile
@@ -2,5 +2,4 @@
 # Makefile for sensor chip drivers.
 #
 
-thermal_sys-objs	+= thermal.o
 obj-$(CONFIG_THERMAL)		+= thermal_sys.o
diff --git a/drivers/thermal/thermal.c b/drivers/thermal/thermal_sys.c
similarity index 100%
rename from drivers/thermal/thermal.c
rename to drivers/thermal/thermal_sys.c