Add support for IPMI Get Boot Options command

Create new Chassis NetFn file and add basic support
for OPAL to call the IPMI Get Boot Options command.
diff --git a/Makefile b/Makefile
index 97c45e6..1a37c0f 100644
--- a/Makefile
+++ b/Makefile
@@ -11,6 +11,7 @@
 LIB_APP_OBJ = apphandler.o     \
               sensorhandler.o  \
               storagehandler.o \
+              chassishandler.o \
               dcmihandler.o    \
               ipmisensor.o     \
               storageaddsel.o  \