glsl: Expose gl_MaxTess{Control,Evaluation}AtomicCounters.

glsl: Expose gl_MaxTess{Control,Evaluation}AtomicCounters.

... with only ARB_shader_atomic_counters.

I expected to see interactions with ARB_tessellation_shader in the
ARB_shader_atomic_counters spec, but they do not exist. It seems that we
should unconditionally expose these variables in the presence of
ARB_shader_atomic_counters:

   gl_MaxTessControlAtomicCounters
   gl_MaxTessEvaluationAtomicCounters

This partially reverts commit da7adb99e8. The commit also affected
gl_MaxTessControlImageUniforms and gl_MaxTessEvaluationImageUniforms
similarly but the ARB_shader_image_load_store spec does list an
interaction with ARB_tessellation_shader.

Cc: "11.0" <mesa-stable@lists.freedesktop.org>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=92095
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
(cherry picked from commit d6bb46bbe8e4ef90dedc5a04c7434a8113c10a8b)