msm: qmi: Add infrastructure to enable QMI service development

1) Add interface functions to register & unregister a service.
2) Add interface functions to send response and indication messages.
3) Add a control port per endpoint to handle control events like client
removal.
4) Update IPC Router to pass out-of-band data like source address during
notification of events.

Change-Id: I4ed3a06f2646162e73053c858b5269fdd8de436e
Signed-off-by: Karthikeyan Ramasubramanian <kramasub@codeaurora.org>