[mutter] clutter/configure.ac: Remove left-over gbm and drm dependencies

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit 3e03d1e38ebe70868bb2672872c755488ee2d3ab
Author: Jonas Ådahl <jadahl gmail com>
Date:   Thu May 24 17:33:15 2018 +0200

    clutter/configure.ac: Remove left-over gbm and drm dependencies
    
    The gbm and drm facing code has since long been moved into mutter.

 clutter/configure.ac | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)
---
diff --git a/clutter/configure.ac b/clutter/configure.ac
index fa20366cf..c88dac271 100644
--- a/clutter/configure.ac
+++ b/clutter/configure.ac
@@ -151,9 +151,8 @@ AS_IF([test "x$enable_wayland_egl_server" = "xyes"],
       [
         CLUTTER_BACKENDS="$CLUTTER_BACKENDS egl"
         SUPPORT_EGL=1
-        AC_DEFINE([CLUTTER_EGL_BACKEND_GENERIC], [1], [Use Generic EGL backend])
 
-        BACKEND_PC_FILES="$BACKEND_PC_FILES wayland-egl wayland-server libdrm gbm"
+        BACKEND_PC_FILES="$BACKEND_PC_FILES wayland-egl wayland-server"
 
         SUPPORT_WAYLAND_COMPOSITOR=1
         CLUTTER_CONFIG_DEFINES="$CLUTTER_CONFIG_DEFINES