Add camera as an ATRACE tag

Change-Id: Idb45cad8aceed00ff957f8506081f877d39cf1a6
diff --git a/systrace.py b/systrace.py
index 8586caf..af82c6f 100755
--- a/systrace.py
+++ b/systrace.py
@@ -23,6 +23,7 @@
   'sync':     1<<7,
   'audio':    1<<8,
   'video':    1<<9,
+  'camera':   1<<10,
 }
 
 def main():