oem-ibm: Check if a FRU is IBM specific

The major difference between the standard FRUs
and the IBM specific FRUs is the format in which
the VPD data is written and its model type.
If the model property is filled it is a IBM specific FRU,
if not then that can be an industry standard FRU.

Change-Id: I9c01b99e37107bc3caeb88336626bc9e514e78f0
Signed-off-by: Sampa Misra <sampmisr@in.ibm.com>