[KMSDRM] Enable full OpenGL detection (MESA/libglvnd) on both the make and cmake buildsystems.

CMakeLists.txt

@@ -1197,6 +1197,7 @@ elseif(UNIX AND NOT APPLE AND NOT ANDROID AND NOT RISCOS)
     # Need to check EGL before checking KMSDRM because KMSDRM depends on it.
     CheckEGLKMSDRM()
     CheckKMSDRM()
+    CheckOpenGLKMSDRM()
   endif()
 
   if(UNIX)