openpower-libhei: srcrev bump 734cfe9585..abc51c2b6f

Zane Shelley (2):
      Externalize chip data file keyword constant
      Copied Chip Data XML from Hostboot project

(From meta-openpower rev: 590bcd28384341c96d6fb5599c8a7418c024648c)

Change-Id: Iab28c2bc2954d2b16b65e4ba7dcb1e75892447bb
Signed-off-by: Andrew Geissler <openbmcbump-github@yahoo.com>
Signed-off-by: Andrew Geissler <geissonator@yahoo.com>