meson: kmsro: require dri3 for X11
The current implementation in kmsro relies on buffer sharing using WINSYS_HANDLE_TYPE_FD, which in x11 is only used by default when dri3 is enabled. Since the current implementation will not work without it, we can prevent user error by checking that it is not disabled at configuration time.
There is some more context in #4861 (closed) for why we are proposing this. I could reproduce that with both lima and panfrost.
Closes #4861 (closed)