phosphor-logging: srcrev bump 51c9263f08..31eed996da

Gunnar Mills (1):
      Update object-mapper.md link

Matt Spinler (10):
      PEL: Represent the SRC ASCII string field
      PEL: FRU identity SRC substructure
      PEL: Add string accessors to MTMS class
      PEL: Add Stream ops for std::vector<char>
      PEL: Power controlling enc SRC substructure
      PEL: MRU callout SRC substructure
      PEL: SRC FRU callout structure
      PEL: SRC callouts subsection object
      PEL: Add SRC PEL section class
      PEL: Initialize PrivateHeader fields in ctor

(From meta-phosphor rev: 4131d42dc94b2097c79e9665ee906994a9af0920)

Change-Id: I02f34356874cb8310ec0a226c74b80d2afc324e4
Signed-off-by: Andrew Geissler <openbmcbump-github@yahoo.com>
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>