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: 2421602
Change-Id: I947ed5b0fe5705e5223d75b0ea8aafb36113ca5a
Signed-off-by: Deepak Kumar Singh <deesin@codeaurora.org>