ARM: dts: msm8916: Add support for voice svc driver

Add a new deivce that can be used by the voice svc
driver to allow userspace client to read/write voice
services' responses/requests

CRs-fixed: 642690
Change-Id: Ied9a7db89adef5e7d9276a4215734af12cfa24c2
Signed-off-by: Karthik Reddy Katta <a_katta@codeaurora.org>