loader: link with OneCore umbrella library

loader: link with OneCore umbrella library

This change makes loader use OneCore umbrella[2] library, common
to all Windows 10 devices and required with for Universal
Windows drivers[1].

As this change may not be compatible with previous versions of
Windows, it's enabled via CMAKE option:
   -DENABLE_WIN10_ONECORE=1

[2] https://msdn.microsoft.com/en-us/library/windows/desktop/mt654039(v=vs.85).aspx
[1] https://docs.microsoft.com/en-us/windows-hardware/drivers/develop/getting-started-with-universal-drivers

Change-Id: Ib677face131ab2edb3e8cd2f764fe4e0ca44cecc