This removes the CM_Register_Notification code on WinRT. Note
that this API _is_ available to UWP apps as of Windows 10.0.17763
(version 1809, released October 2018), according to:
https://docs.microsoft.com/en-us/uwp/win32-and-com/win32-apis#apis-from-api-ms-win-devices-config-l1-1-1dll
So it might be worth readding with some sort of preprocessor check
for minimum targeted version, or whatever is appropriate for WinRT
development.
Ryan C. Gordon
834a84fabb