Use generated bindings for Led Group manager

This extends generated sdbusplus interface and provides implementation for
handling LED group operations.

Change-Id: I9e6f83f2f801de24d33937bc651228b1c0ccdc37
Signed-off-by: Vishwanatha Subbanna <vishwa@linux.vnet.ibm.com>
diff --git a/Makefile.am b/Makefile.am
index e146a74..1557aad 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -3,7 +3,9 @@
 
 phosphor_ledmanager_SOURCES = \
                 led-main.cpp  \
-                led-manager.cpp
+                manager.cpp \
+                group.cpp \
+                xyz.openbmc_project.Led.Group.cpp
 
 BUILT_SOURCES = led-gen.hpp
 CLEANFILES = led-gen.hpp