Input: gpio_keys - fix misnamed function parameter 'dev'

Input: gpio_keys - fix misnamed function parameter 'dev'

Fixes the following W=1 kernel build warning(s):

 drivers/input/keyboard/gpio_keys.c:119: warning: Function parameter or member 'dev' not described in 'get_bm_events_by_type'
 drivers/input/keyboard/gpio_keys.c:119: warning: Excess function parameter 'input' description in 'get_bm_events_by_type'

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20201104162427.2984742-12-lee.jones@linaro.org
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>