ACPI / button: Add document for ACPI control method lid device restrictions

This patch adds documentation for the usage model of the control method lid
device on some buggy platforms.

Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Acked-by: Benjamin Tissoires <benjamin.tissoires@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>