Generate local elog-errors header file

Use elog-gen.py, elog-gen-template.mako.hpp, error yaml files
from SDK to build local elog-errors.hpp file

Change-Id: I9e22633c8b6a8eacc754771883de82e8b476def3
Signed-off-by: Marri Devender Rao <devenrao@in.ibm.com>
diff --git a/configure.ac b/configure.ac
index 2802742..ca6d94e 100644
--- a/configure.ac
+++ b/configure.ac
@@ -11,9 +11,14 @@
 AC_PROG_INSTALL
 AC_PROG_MAKE_SET
 
-# Check for compiler, packages only during target build.
-# As the packages are not available on the host do not
-# perform checks during native build.
+# Generate elog-errors.hpp if gen_errors optional feature is enabled
+AC_ARG_ENABLE([gen_errors],
+    AS_HELP_STRING([--enable-gen_errors], [Enable elog-errors.hpp generation ]),
+    [],[gen_errors=yes])
+AM_CONDITIONAL([GEN_ERRORS], [test "x$enable_gen_errors" != "xno"])
+
+# Check for compiler, packages only when install_error_yaml optional feature
+# is disabled
 AC_ARG_ENABLE([install_error_yaml],
     AS_HELP_STRING([--enable-install_error_yaml], [Enable installing error yaml file]),
     [], [install_error_yaml=no])