Input: pmic8xxx-keypad - fix kernel-doc formatting

Input: pmic8xxx-keypad - fix kernel-doc formatting

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

 drivers/input/keyboard/pmic8xxx-keypad.c:106: warning: Function parameter or member 'num_rows' not described in 'pmic8xxx_kp'
 drivers/input/keyboard/pmic8xxx-keypad.c:106: warning: Function parameter or member 'num_cols' not described in 'pmic8xxx_kp'
 drivers/input/keyboard/pmic8xxx-keypad.c:106: warning: Function parameter or member 'input' not described in 'pmic8xxx_kp'
 drivers/input/keyboard/pmic8xxx-keypad.c:106: warning: Function parameter or member 'regmap' not described in 'pmic8xxx_kp'
 drivers/input/keyboard/pmic8xxx-keypad.c:106: warning: Function parameter or member 'key_sense_irq' not described in 'pmic8xxx_kp'
 drivers/input/keyboard/pmic8xxx-keypad.c:106: warning: Function parameter or member 'key_stuck_irq' not described in 'pmic8xxx_kp'
 drivers/input/keyboard/pmic8xxx-keypad.c:106: warning: Function parameter or member 'keycodes' not described in 'pmic8xxx_kp'
 drivers/input/keyboard/pmic8xxx-keypad.c:106: warning: Function parameter or member 'dev' not described in 'pmic8xxx_kp'
 drivers/input/keyboard/pmic8xxx-keypad.c:106: warning: Function parameter or member 'keystate' not described in 'pmic8xxx_kp'
 drivers/input/keyboard/pmic8xxx-keypad.c:106: warning: Function parameter or member 'stuckstate' not described in 'pmic8xxx_kp'
 drivers/input/keyboard/pmic8xxx-keypad.c:106: warning: Function parameter or member 'ctrl_reg' not described in 'pmic8xxx_kp'

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20201104162427.2984742-21-lee.jones@linaro.org
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>