Input: wistron - convert to use input-polldev

Switch to using input-polldev skeleton instead of implementing
polling loop by itself.

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
diff --git a/drivers/input/misc/Kconfig b/drivers/input/misc/Kconfig
index 4326f53..9b26574 100644
--- a/drivers/input/misc/Kconfig
+++ b/drivers/input/misc/Kconfig
@@ -65,6 +65,7 @@
 config INPUT_WISTRON_BTNS
 	tristate "x86 Wistron laptop button interface"
 	depends on X86 && !X86_64
+	select INPUT_POLLDEV
 	select NEW_LEDS
 	select LEDS_CLASS
 	help