msm: ipc: Update HELLO message processing

When IPC Router receives a HELLO message from a remote IPC Router, the
protocol is to send a list of servers registered locally and registered
outside the mesh network where the HELLO message is received. Currently
the implementation does not follow this protocol strictly and hence
correct the implementation.

CRs-Fixed: 414147
Change-Id: I75aa089b152baea0925d127b1d9deb6684677cfa
Signed-off-by: Karthikeyan Ramasubramanian <kramasub@codeaurora.org>