Buttons on MSI WindTop AE1900-WT (also called MS-6638) are currently not supported on Linux

After long time of investigations, I found these buttons are handled by WMI. I wrote a WMI module for MSI.

Currently, there is an issue with interrupts. Buttons send between 25 and 30 interrupts when they are pressed. Kernel should forward only one event for each key press.

In add, this module should support Brightness.