soc: qcom: smem: validate fields of shared structures

Structures in shared memory that can be modified by remote
processors may have untrusted values, they should be validated
before use.

Adding proper validation before using fields of shared
structures.

CRs-Fixed: 2421611
Change-Id: Ifed71c506a26105eac3db9ee35f086d7dbf5a3a3
Signed-off-by: Deepak Kumar Singh <deesin@codeaurora.org>