elog-gen.py : read multiple error yaml files

This change enables the elog-gen script to look at more than one error
yaml file (and corresponding metadata yaml file). The input to the
script had to be changed to a yaml directory, containing
error yaml files, instead of a single error yaml file.

The reason to support reading multiple error yaml files is that,
without this, applications have to all dump their errors in a single big
error yaml file. Now it's possible to write application/domain specific
error yaml files; they just need to be exported to the same location,
from where elog-gen.py can pick them.

Change-Id: I9418bf0e0b54a7b7f7701b337649cb8eb4c54913
Signed-off-by: Deepak Kodihalli <dkodihal@in.ibm.com>
diff --git a/Makefile.am b/Makefile.am
index f96d2cf..ea96862 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -23,9 +23,8 @@
 logging_test_LDFLAGS = $(SYSTEMD_LIBS)
 phosphor_log_manager_LDFLAGS = $(SYSTEMD_LIBS)
 
-ELOG_YAML ?= xyz/openbmc_project/Example/Elog.errors.yaml
 ELOG_MAKO ?= elog-gen-template.mako.hpp
-ELOG_YAML_DIR ?= tools/example/
+ELOG_YAML_DIR ?= tools/example/xyz/openbmc_project/Example/
 ELOG_TEMPLATE_DIR ?= tools/phosphor-logging/templates/
 REQ_FILES_TO_GEN ?= ${abs_srcdir}/tools/elog-gen.py\
 	${abs_srcdir}/$(ELOG_YAML_DIR)/$(ELOG_YAML)\
@@ -36,6 +35,6 @@
 EXTRA_DIST = $(REQ_FILES_TO_GEN)
 
 elog-gen.hpp: $(REQ_FILES_TO_GEN)
-	$(AM_V_at)${abs_srcdir}/tools/elog-gen.py -r ${abs_srcdir}/${ELOG_YAML_DIR} -t ${abs_srcdir}/${ELOG_TEMPLATE_DIR} -e $(ELOG_YAML) -m $(ELOG_MAKO) -o ${abs_srcdir}/elog-gen.hpp
+	$(AM_V_at)${abs_srcdir}/tools/elog-gen.py -y ${abs_srcdir}/${ELOG_YAML_DIR} -t ${abs_srcdir}/${ELOG_TEMPLATE_DIR} -m $(ELOG_MAKO) -o ${abs_srcdir}/elog-gen.hpp
 
 SUBDIRS = test