configure: remove unused AC_SUBST variables

v2: Rebase.

Signed-off-by: Emil Velikov <emil.velikov@collabora.com>
Reviewed-by: Nicolai Hähnle <nicolai.haehnle@amd.com> (v1)
diff --git a/configure.ac b/configure.ac
index 450fca1..8cdaa6a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1997,7 +1997,6 @@
 dnl
 dnl EGL configuration
 dnl
-EGL_CLIENT_APIS=""
 
 if test "x$enable_egl" = xyes; then
     EGL_LIB_DEPS="$DLOPEN_LIBS $SELINUX_LIBS $PTHREAD_LIBS"
@@ -2211,15 +2210,6 @@
 dnl
 AM_CONDITIONAL(HAVE_GALLIUM, test -n "$with_gallium_drivers")
 
-case "x$enable_opengl$enable_gles1$enable_gles2" in
-x*yes*)
-    EGL_CLIENT_APIS="$EGL_CLIENT_APIS "'$(GL_LIB)'
-    ;;
-esac
-
-AC_SUBST([VG_LIB_DEPS])
-AC_SUBST([EGL_CLIENT_APIS])
-
 dnl
 dnl EGL Platforms configuration
 dnl