A module egl_display must only provide EGL displays where eglTerminate()
can be called, even if other modules are using EGL (typically because it
is internally refcounted).

This is always the case on Android, so egl_display was initially only
enabled on Android:
https://android.googlesource.com/platform/frameworks/native/+/master/opengl/libs/EGL/egl_display.cpp

But this may also be the case on other platforms which support
EGL_KHR_display_reference:
https://www.khronos.org/registry/EGL/extensions/KHR/EGL_KHR_display_reference.txt



Co-authored-by: Alexandre Janniaux <ajanni@videolabs.io>
Signed-off-by: Alexandre Janniaux <ajanni@videolabs.io>