Thermal: spear: Remove redundant platform_set_drvdata()

Commit 0998d06310 (device-core: Ensure drvdata = NULL when no
driver is bound) removes the need to set driver data field to
NULL.

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Cc: Vincenzo Frascino <vincenzo.frascino@st.com>
Acked-by: Eduardo Valentin <eduardo.valentin@ti.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

drivers/thermal/spear_thermal.c

@@ -174,7 +174,6 @@ static int spear_thermal_exit(struct platform_device *pdev)
 	struct spear_thermal_dev *stdev = spear_thermal->devdata;
 
 	thermal_zone_device_unregister(spear_thermal);
-	platform_set_drvdata(pdev, NULL);
 
 	/* Disable SPEAr Thermal Sensor */
 	actual_mask = readl_relaxed(stdev->thermal_base);