EGL: add the EGL_ANDROID_framebuffer_target enum

Change-Id: Id8b1b114e2a7a88956b857c63a0429e9b33fdb5c
diff --git a/opengl/libs/EGL/egl_display.cpp b/opengl/libs/EGL/egl_display.cpp
index 8fd5af1..7ca9e40 100644
--- a/opengl/libs/EGL/egl_display.cpp
+++ b/opengl/libs/EGL/egl_display.cpp
@@ -59,6 +59,7 @@
 
 // extensions not exposed to applications but used by the ANDROID system
 //      "EGL_ANDROID_recordable "               // mandatory
+//      "EGL_ANDROID_framebuffer_target "       // mandatory for HWC 1.1
 //      "EGL_ANDROID_blob_cache "               // strongly recommended
 //      "EGL_ANDROID_native_fence_sync "        // strongly recommended
 //      "EGL_IMG_hibernate_process "            // optional