Create framework for IPMI OEM extension commands

IPMI has four commands that accept "OEM Parameters". The existing IPMI
command handlers do not account for these OEM extensions. This commit
adds OEM Parameters support for the Set/Get LAN Configuration
Parameters commands.

Tested:

ipmitool raw 0xc 1 3 0xc0 0 ;; received 0x80 return code
ipmitool raw 0xc 2 3 0 0    ;; received 0x80 return code

Change-Id: I81135b6d3269cec98ffd7754a03201a74c436c11
Signed-off-by: Johnathan Mantey <johnathanx.mantey@intel.com>
diff --git a/configure.ac b/configure.ac
index b759320..04c48b8 100644
--- a/configure.ac
+++ b/configure.ac
@@ -229,6 +229,21 @@
 )
 AM_CONDITIONAL(FEATURE_LIBUSERLAYER, [test "x$enable_libuserlayer" != "xno"])
 
+# When enable-transport-oem flag is set, the transporthandler_oem.cpp contents
+# are compiled and added to the project. The transporthandler_oem.cpp file is
+# copied from your own customization layer in the
+# phosphor-ipmi-host_%.bbappend file. It is not necessary to create this file
+# unless OEM Parameter extensions are required.
+AC_ARG_ENABLE([transport_oem],
+    [  --enable-transport-oem   Enable/disable OEM Parameter extensions],
+    [case "${enableval}" in
+      yes) transport_oem=true ;;
+      no) transport_oem=false ;;
+      *) AC_MSG_ERROR([bad value ${enableval} for --enable-transport_oem]) ;;
+      esac],[transport_oem=false]
+      )
+AM_CONDITIONAL([FEATURE_TRANSPORT_OEM], [test x$transport_oem = xtrue])
+
 # Create configured output
 AC_CONFIG_FILES([
     Makefile