mesa: Enable GL_MESA_framebuffer_flip_y for GL 4.3

Extend MESA_framebuffer_flip_y to be used with OpenGL versions 4.3 and
higher. OpenGL 4.3 adds FramebufferParameteri needed by this extension.

Reviewed-by: Fritz Koenig <frkoenig@google.com>
Reviewed-by: Matt Turner <mattst88@gmail.com>