msm: camera: icp: Add support for downscale inputs

Multiple input sync objects are sent in IPE
packets to support multiple outputs from IFE and BPS.
ICP driver merges all input sync objects and creates
a merged sync object to wait for the outputs.

Change-Id: I88b285807680c3d5481af52157c4e5f2819d463d
Signed-off-by: Suresh Vankadara <svankada@codeaurora.org>