egl: hide entrypoints that shouldn't be exported when using glvnd

From GLVND author:
> From a functional standpoint, exporting additional symbols doesn't
> really matter, since libglvnd will load the vendor libraries with
> RTLD_LOCAL.

Suggested-by: Kyle Brenneman <kbrenneman@nvidia.com>
Signed-off-by: Eric Engestrom <eric.engestrom@intel.com>
Acked-by: Kyle Brenneman <kbrenneman@nvidia.com>
1 file changed