pytools: obmcutil: Drop ElementTree and json imports

Change-Id: I2e310eef36eb7bcea58d1567dcf3efe9a9dbeeb8
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
diff --git a/pytools/obmcutil b/pytools/obmcutil
index 677d997..42f34e5 100644
--- a/pytools/obmcutil
+++ b/pytools/obmcutil
@@ -2,8 +2,6 @@
 
 import sys
 import dbus
-import json
-import xml.etree.ElementTree as ET
 
 dbus_objects = {
     'power': {