msm: smd: convert to secured smem feature

The shared memory (smem) driver provides a feature where point-to-point
smem items shared between Linux apps and one other remote processor are
protected against a number of attacks by security hardware, provided system
support exists.  Clients of the smem driver must elect to use this feature
if applicable.

SMD is a point-to-point communication protocol to which the security
feature applies.  Update SMD to make use of the security feature.

Change-Id: I5eafb832e83489bb1e4a8f70e4103416c540953d
Signed-off-by: Jeffrey Hugo <jhugo@codeaurora.org>