Event-handling: Forward node down event to provider to take action.
Event-handling: Forward node down event to provider to take action.

This patch forwards node down event to provider, so that it can
take appropriate action depending on its need.

Change-Id: I5587310d615cf74146b62df07f9f8ef17a768cb2
Signed-off-by: Darshan N <d2c6d450ab98b078f2f1942c995e6d92dd504bc8@gmail.com>

skyrings/skyring,skyrings/skyring,skyrings/skyring,skyrings/skyring