msm: camera: isp: Fixed dual ife stripe wm update

Added check in dual ife stripe update config to check
whether the port id is valid or not.  If not valid, we
will not update the config for that write master.

Change-Id: Ie76e58ed3304c1698e2029038390d2131153be7b
Signed-off-by: Mark Woh <mwoh@codeaurora.org>