diag: Validate the dci client before sending dci packet

Ensure dci client's tag used is a valid one by validating against
its status before sending the dci packet to client.

Change-Id: Ia673e8b548e441eb907820dc395c22b7f1b75d10
Signed-off-by: Manoj Prabhu B <quic_bmanoj@quicinc.com>