platform/x86: fujitsu-laptop: autodetect LCD interface on all models

Presence of ACPI method SBL2 should be checked on all models rather than
just the ones with predefined hotkey keycode overrides.  Move most of
dmi_check_cb_common() to acpi_fujitsu_bl_add().  Adjust indentation to
make checkpatch happy.

Signed-off-by: Alan Jenkins <alan-jenkins@tuffmail.co.uk>
[kempniu: rebase patch, rewrite commit message]
Signed-off-by: Michał Kępień <kernel@kempniu.pl>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Jonathan Woithe <jwoithe@just42.net>