Fix the dbus signature used for setting postcodes

- With 9a96970ebb93eb1f495c200801343a4d1c53977c PDI change,
  the dbus signature of raw post codes has been changed from
  uint64 to struct[uint64,array[byte]] where the array[byte] is
  the secondary post code.

- The intent behind this commit is to fix the code based on the
  latest PDI change.

Signed-off-by: Manojkiran Eda <manojkiran.eda@gmail.com>
Change-Id: I46dfbf643ad138c373d3826d3504b4a26866a5bf
1 file changed