msm: Fix for audio loss during WLAN & LTE call handover

Current APR implementation doesn't support session based
multiple service registrations. The apr_deregister()
function sets the destination and client IDs to zero, if
deregister is called for a single service instance.
Fix this by registering for dummy services in voice SVC
driver.

CRs-fixed: 690921
Change-Id: I9e37e268a7ed1787f0e2abc6a6822aa40571f0ca
Signed-off-by: Karthik Reddy Katta <a_katta@codeaurora.org>