platform/x86: ideapad-laptop: Add fn-lock setting

Some of latest Lenovo ideapad laptops do not have UEFI/BIOS setting for
switching fn-lock mode. This commit adds related acpi calls to ideapad
platform driver. However setting is available via sysfs.

Signed-off-by: Oleg Keri <ezhi99@gmail.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>