EGL: sync headers with Khronos

EGL: sync headers with Khronos

Since [1], EGL removed the inclusion of the Xlib headers by default.
The logic is now reversed, and the call has to define USE_X11 to include the
Xlib headers instead of EGL_NO_X11_HEADERS to prevent the inclusion.

[1]: https://github.com/KhronosGroup/EGL-Registry/pull/130/commits/3670d645f4a26a0a9e87e7f3a8608e7cc1d53b5b

Signed-off-by: Simon Zeni <simon@bl4ckb0ne.ca>
Reviewed-by: Eric Engestrom <eric@igalia.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/18848>