Fix cull_distance.coverage on pre-GL4 drivers

Components: OpenGL

VK-GL-CTS issue: 2673

Affects: KHR-GL*.cull_distance.coverage
Change-Id: I0e5019210d21ebb548159d1aa1aa633be5fe66a6
diff --git a/external/openglcts/modules/gl/gl3cCullDistanceTests.cpp b/external/openglcts/modules/gl/gl3cCullDistanceTests.cpp
index 3b82996..6673b26 100644
--- a/external/openglcts/modules/gl/gl3cCullDistanceTests.cpp
+++ b/external/openglcts/modules/gl/gl3cCullDistanceTests.cpp
@@ -746,9 +746,10 @@
 			std::string gs_body = gs_body_template;
 
 			static const glw::GLchar* tc_body_template =
-				"#version 400\n"
+				"#version 150\n"
 				"\n"
 				"#extension GL_ARB_cull_distance : require\n"
+				"#extension GL_ARB_tessellation_shader : require\n"
 				"\n"
 				"layout(vertices = 1) out;\n"
 				"\n"
@@ -771,9 +772,10 @@
 			std::string tc_body = tc_body_template;
 
 			static const glw::GLchar* te_body_template =
-				"#version 400\n"
+				"#version 150\n"
 				"\n"
 				"#extension GL_ARB_cull_distance : require\n"
+				"#extension GL_ARB_tessellation_shader : require\n"
 				"\n"
 				"flat in  int INPUT_TE_NAME[];\n"
 				"flat out int out_te;\n"