Add drm support to minui

Bug: 22231636

Change-Id: I103c8e906b7dd9862b7bb89d8642268e9a3006b4
Signed-off-by: Stéphane Marchesin <marcheu@chromium.org>
diff --git a/minui/graphics.cpp b/minui/graphics.cpp
index f09f1c6..c0eea9e 100644
--- a/minui/graphics.cpp
+++ b/minui/graphics.cpp
@@ -369,6 +369,11 @@
     }
 
     if (!gr_draw) {
+        gr_backend = open_drm();
+        gr_draw = gr_backend->init(gr_backend);
+    }
+
+    if (!gr_draw) {
         gr_backend = open_fbdev();
         gr_draw = gr_backend->init(gr_backend);
         if (gr_draw == NULL) {