platform/x86: peaq-wmi: Add DMI check before binding to the WMI interface

It seems that the WMI GUID used by the PEAQ 2-in-1 WMI hotkeys is not
as unique as a GUID should be and is used on some other devices too.

This is causing spurious key-press reports on these other devices.

This commits adds a DMI check to the PEAQ 2-in-1 WMI hotkeys driver to
ensure that it is actually running on a PEAQ 2-in-1, fixing the
spurious key-presses on these other devices.

BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=1497861
BugLink: https://bugzilla.suse.com/attachment.cgi?id=743182


Cc: stable@vger.kernel.org
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>