Add the timer class

Usage would be instantiate the timer with the call back
and start the timer with the time.
callback will be called once the timer expires.

Change-Id: I09394264ba18bd90a1c101fc77bc45f7268c5db0
Signed-off-by: Ratan Gupta <ratagupt@in.ibm.com>
diff --git a/Makefile.am b/Makefile.am
index aacb465..eac5692 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -21,7 +21,8 @@
 		system_configuration.hpp \
 		dhcp_configuration.hpp \
 		vlan_interface.hpp \
-		rtnetlink_server.hpp
+		rtnetlink_server.hpp \
+		timer.hpp
 
 phosphor_network_manager_SOURCES = \
 		ethernet_interface.cpp \
@@ -37,7 +38,8 @@
 		config_parser.cpp \
 		dhcp_configuration.cpp \
         vlan_interface.cpp \
-		rtnetlink_server.cpp
+		rtnetlink_server.cpp \
+		timer.cpp
 
 CLEANFILES = \
 		xyz/openbmc_project/Network/VLAN/Create/server.cpp \