mfd: tc6393xb: Remove unnecessary platform_set_drvdata()

The driver core clears the driver data to NULL after device_release
or on probe failure, since commit 0998d0631001288a5974afc0b2a5f568bcdecb4d
(device-core: Ensure drvdata = NULL when no driver is bound).
Thus, it is not needed to manually clear the device driver data to NULL.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
diff --git a/drivers/mfd/tc6393xb.c b/drivers/mfd/tc6393xb.c
index 15e1463..a563dfa 100644
--- a/drivers/mfd/tc6393xb.c
+++ b/drivers/mfd/tc6393xb.c
@@ -756,7 +756,6 @@
 	clk_disable(tc6393xb->clk);
 	iounmap(tc6393xb->scr);
 	release_resource(&tc6393xb->rscr);
-	platform_set_drvdata(dev, NULL);
 	clk_put(tc6393xb->clk);
 	kfree(tc6393xb);