Input: mc13783-pwrbutton - file headers are not good candidates for kernel-doc

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

 drivers/input/misc/mc13783-pwrbutton.c:32: warning: cannot understand function prototype: 'struct mc13783_pwrb '
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20201112110204.2083435-4-lee.jones@linaro.orgSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

drivers/input/misc/mc13783-pwrbutton.c

-/**
+/*
  * Copyright (C) 2011 Philippe Rétornaz
  *
  * Based on twl4030-pwrbutton driver by: