Input: eeti_ts - use gpio_get_value_cansleep

We are reading GPIO state in a non-atomic context (workqueue), so we can
use "cansleep" variant, and thus make the driver available on systems where
GPIO controllers require sleeping when reading GPIO state.

Reviewed-by: Daniel Mack <daniel@zonque.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>