Input: tps6507x-ts - select INPUT_POLLDEV

Since the driver was converted to polled device infrastructure we need
to make sure it is enabled.
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

drivers/input/touchscreen/Kconfig

@@ -909,6 +909,7 @@ config TOUCHSCREEN_STMPE
 config TOUCHSCREEN_TPS6507X
 	tristate "TPS6507x based touchscreens"
 	depends on I2C
+	select INPUT_POLLDEV
 	help
 	  Say Y here if you have a TPS6507x based touchscreen
 	  controller.