msi-laptop: fix section mismatch in reference from the function load_scm_model_init

There have section mismatch warning message shows up when building
the kernel with make CONFIG_DEBUG_SECTION_MISMATCH=y.

The problem is the load_scm_model_init() calls msi_laptop_input_setup()
which is an __init function, but load_scm_model_init() lacks a __init
annotation.

This patch add __init on load_scm_model_init() to avoid warning message.

Cc: Matthew Garrett <mjg@redhat.com>
Cc: Dmitry Torokhov <dtor@mail.ru>
Cc: Corentin Chary <corentincj@iksaif.net>
Cc: Thomas Renninger <trenn@suse.de>
Signed-off-by: Lee, Chun-Yi <jlee@novell.com>
Signed-off-by: Matthew Garrett <mjg@redhat.com>