IntelFsp2Pkg: rename GetFspVpdDataPointer() to GetFspCfgRegionDataPointer()

IntelFsp2Pkg: rename GetFspVpdDataPointer() to GetFspCfgRegionDataPointer()

FSP2.0 removed VPD concept.
Rename GetFspVpdDataPointer() to GetFspCfgRegionDataPointer() to follow FSP2.0
specification (CfgRegionOffset).

Cc: Giri P Mudusuru <giri.p.mudusuru@intel.com>
Cc: Amy Chan <amy.chan@intel.com>
Cc: Satya Yarlagadda <satya.p.yarlagadda@intel.com>
Cc: Maurice Ma <maurice.ma@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jiewen Yao <jiewen.yao@intel.com>
Reviewed-by: Giri P Mudusuru <giri.p.mudusuru@intel.com>
Reviewed-by: Amy Chan <amy.chan@intel.com>