msm: ipa: check the nat table offset sizes

Before creating nat table, check the table offsets
passed by user space against total memory size
allocated  to avoid security issues.

Change-Id: I7588087ad30038225696dd4b6c793cd8dda7d569
Acked-by: Sunil Paidimarri <hisunil@qti.qualcomm.com>
Signed-off-by: Skylar Chang <chiaweic@codeaurora.org>