scons: Remove gles option.

It's broken, and WGL state tracker is always built with GLES support
noawadays.

Reviewed-by: Brian Paul <brianp@vmware.com>
Reviewed-by: Roland Scheidegger <sroland@vmware.com>
diff --git a/src/mesa/SConscript b/src/mesa/SConscript
index 5a21b64..eaf23fb 100644
--- a/src/mesa/SConscript
+++ b/src/mesa/SConscript
@@ -27,10 +27,8 @@
     env.Append(CPPDEFINES = [
         '_GDI32_', # prevent gl* being declared __declspec(dllimport) in MS headers
         'BUILD_GL32', # declare gl* as __declspec(dllexport) in Mesa headers
+        '_GLAPI_NO_EXPORTS', # prevent _glapi_* from being declared __declspec(dllimport)
     ])
-    if not env['gles']:
-        # prevent _glapi_* from being declared __declspec(dllimport)
-        env.Append(CPPDEFINES = ['_GLAPI_NO_EXPORTS'])
 
 # parse Makefile.sources
 source_lists = env.ParseSourceList('Makefile.sources')