Required by OpenXR. A VkPhysicalDevice or an adapter LUID + feature
level pair should be adoptable while leaving the rest (device, queue,
etc. setup) to QRhi as normal.
Change-Id: Iada0972671b037b4efb03e7831b7c9b8c5f2393d
Reviewed-by: Andy Nichols <andy.nichols@qt.io>