vaapidisplay: add drm backend support

1. client and yami shares the same display when it provides both native
   display (x11 Display or drm fd) and display type in setNativeDisplay().
   client owns the native display
2. when client set native display type only, yami will create a native
   display and owns it.
3. when client doesn't set any native display, or set display type to
   NATIVE_DISPLAY_AUTO; yami will try to open a x11 display first. if fail,
   drm display will try next

4. A x11 display is compatible to drm display, while not reverse.
   it means, when there is a VADisplay created from x11 display,
   yami will not create a new display when drm display is requested,
   simplely reuse the VADisplay.