Input: max8925_onkey - don't mark comment as kernel-doc

Input: max8925_onkey - don't mark comment as kernel-doc

Change the comment to a normal (non-kernel-doc) comment to avoid
these kernel-doc warnings:

max8925_onkey.c:2: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
 * MAX8925 ONKEY driver
max8925_onkey.c:2: warning: missing initial short description on line:
 * MAX8925 ONKEY driver

Fixes: 3734574cac100 ("Input: enable onkey driver of max8925")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/r/20211002045943.9406-1-rdunlap@infradead.org
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>