msm: camera: core: Pass ctx hw map in start args

Validate input args and fix issue where ctx_to_hw_map
handle passing was missing while calling start().
Without passing hw_map pointer hw_mgr drivers cannot
know corresponding hw context and would fail to start.

Change-Id: Iecaee9906b29fdec3b65a26860ccf75599a7149c
Signed-off-by: Pavan Kumar Chilamkurthi <pchilamk@codeaurora.org>