qcacmn: Properly export dp_peer API

Currently some of the public functions in dp_peer.c do not have their
prototypes exposed in a header file. In addition clients of these
functions currently have local prototypes. Fix these issues by adding
the prototypes to dp_peer.h.

Change-Id: I461cf69024da56fad57b75a325775ecd68872c8e
CRs-Fixed: 1108085
3 files changed