bmc: add states for updating firmware

Add three states to the bmc's state machine for handling a controlled
update process.  Pending, Started, Completed.  Once /flash/verify is
closed after completion (and success), pending is set.  Once
/flash/update is opened, started will be set.  The state machine is not
updated in this patchset to handle these transitions.  This patchset
only defines the new states.

Signed-off-by: Patrick Venture <venture@google.com>
Change-Id: I003ab4a5a921e5bbad9ceb399f8470a6a0961aa1
diff --git a/firmware_handler.hpp b/firmware_handler.hpp
index 2b2c7d3..def20a8 100644
--- a/firmware_handler.hpp
+++ b/firmware_handler.hpp
@@ -98,6 +98,12 @@
         verificationStarted,
         /** The verification process has completed. */
         verificationCompleted,
+        /** The update process is pending. */
+        updatePending,
+        /** The update process has started. */
+        updateStarted,
+        /** The update has completed (optional state to reach) */
+        updatedCompleted,
     };
 
     /**