mtlib/platform.py: Detect xorg.conf files in ozone/freon world

This was breaking platform_GesturesRegressionTests autotest.

BUG=chromium:452991
TEST="test_that <DUT IP> platform_GesturesRegressionTests" passed on
both link (ozone/freon) and lumpy (X11).

Change-Id: I544155330c60377615588199a50a991c862efd1c
Reviewed-on: https://chromium-review.googlesource.com/243961
Reviewed-by: Dennis Kempin <denniskempin@chromium.org>
Commit-Queue: Andrew de los Reyes <adlr@chromium.org>
Tested-by: Andrew de los Reyes <adlr@chromium.org>
diff --git a/mtlib/platform.py b/mtlib/platform.py
index e12bed1..6d05397 100755
--- a/mtlib/platform.py
+++ b/mtlib/platform.py
@@ -145,7 +145,9 @@
     if src_root:
       xorg_conf_path = os.path.join(src_root, xorg_conf_project_path)
     else:
-      xorg_conf_path = '/etc/X11/xorg.conf.d'
+      xorg_conf_path = '/etc/gesture'
+      if not os.path.exists(xorg_conf_path):
+        xorg_conf_path = '/etc/X11/xorg.conf.d'
 
     if xorg_conf_path and 'xorg' in data and 'file' in data['xorg']:
       filename = os.path.join(xorg_conf_path, data['xorg']['file'])