NFC: trf7970a: Remove useless comment

The last entry in the trf7970a_of_match[] table must be an empty
entry to demarcate the end of the table.  Currently, there is a
comment indicating this but it is obvious so remove the comment.
Signed-off-by: Mark Greer <mgreer@animalcreek.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

drivers/nfc/trf7970a.c

@@ -2273,7 +2273,7 @@ static const struct dev_pm_ops trf7970a_pm_ops = {
 
 static const struct of_device_id trf7970a_of_match[] = {
 	{ .compatible = "ti,trf7970a", },
-	{ /* sentinel */ },
+	{},
 };
 MODULE_DEVICE_TABLE(of, trf7970a_of_match);