Add support for Entity Association Record

Adding support for Entity Association Record (SDR type - 0x08h)
This patch includes:
1) Entity Association Record yaml file example
2) Entity Assocation Record related script and mako file changes
3) Adding Entity Association Record in get_sdr IPMI command response

From the host, tested that entity association records can be fetched

Change-Id: I9cf598e5d27d2e8c6751bbaae2176e7c976974b1
Tested: Yes
Signed-off-by: Jaghathiswari Rankappagounder Natarajan <jaghu@google.com>
diff --git a/configure.ac b/configure.ac
index 8ad85f2..471a7be 100644
--- a/configure.ac
+++ b/configure.ac
@@ -97,6 +97,10 @@
 FRUGEN="$PYTHON $srcdir/scripts/fru_gen.py -i $FRU_YAML_GEN"
 AC_SUBST(FRUGEN)
 
+AS_IF([test "x$ENTITY_YAML_GEN" == "x"], [ENTITY_YAML_GEN="entity-example.yaml"])
+ENTITYGEN="$PYTHON $srcdir/scripts/entity_gen.py -i $ENTITY_YAML_GEN"
+AC_SUBST(ENTITYGEN)
+
 AC_DEFINE(CALLOUT_FWD_ASSOCIATION, "callout", [The name of the callout's forward association.])
 AC_DEFINE(BOARD_SENSOR, "/xyz/openbmc_project/inventory/system/chassis/motherboard", [The inventory path to the motherboard fault sensor.])
 AC_DEFINE(SYSTEM_SENSOR, "/xyz/openbmc_project/inventory/system", [The inventory path to the system event sensor.])