Add pre-flight branch config for peach pit

BUG=None
TEST=None

Change-Id: I8bd77e8b2c98bf991dc6b79e112752e9c5570e96
Reviewed-on: https://gerrit.chromium.org/gerrit/51430
Reviewed-by: Katie Roberts-Hoffman <katierh@chromium.org>
Tested-by: Peter Mayo <petermayo@chromium.org>
diff --git a/buildbot/cbuildbot_config.py b/buildbot/cbuildbot_config.py
index e47de17..a3c5595 100755
--- a/buildbot/cbuildbot_config.py
+++ b/buildbot/cbuildbot_config.py
@@ -1030,10 +1030,11 @@
   hw_tests=[],
 )
 
-internal_pfq_branch.add_config('x86-alex-pre-flight-branch',
+internal_pfq_branch.add_config('peach_pit-pre-flight-branch',
+  arm,
   master=True,
   push_overlays=constants.BOTH_OVERLAYS,
-  boards=['x86-alex'],
+  boards=['peach_pit'],
 )
 
 ### Master paladin (CQ builder).