msm: camera: Setting max msm_post timeout to 6.5seconds

Setting MAX timeout to 6.5seconds considering
backend will operate @ .6fps in certain usecases
like Long exposure usecase and isp needs max of 2 frames
to stop the hardware which will be around 3 seconds.

Change-Id: I9a219004dbecd3f42810dcf1200b79f1929b003a
Signed-off-by: Hariram Purushothaman <hariramp@codeaurora.org>