build: generate elog-process-metadata.cpp
build: generate elog-process-metadata.cpp

Add rules to generate and build elog-process-metadata.cpp.

Change-Id: If9b61dfd2fbd731708e41a48428115ee40b12d6b
Signed-off-by: Deepak Kodihalli <54105a30055f1e07853b8ee7a2f0d75d22ed98c1@in.ibm.com>

openbmc/phosphor-logging,openbmc/phosphor-logging,openbmc/phosphor-logging,openbmc/phosphor-logging