msm: camera: smmu: Enhance debug capability for camera memmgr

Improve debugging infrastructure and logging for memory related
issues. There are scenarios where the fd returned after ion_alloc
exists in camera smmu table as being mapped [stale entry].
On such scenarios, this change will return a specific error code to
userspace. The change also propagates the mapped size back to
user space.

CRs-Fixed: 2663114
Change-Id: Ia797b65d1e8ded58dec5b01df07d73262c4cfa95
Signed-off-by: Karthik Anantha Ram <kartanan@codeaurora.org>