crypto: msm: Ensure sha_init is called for HASH operation

Validate that the sha_ctx is initialized before any SHA operation
(update, final) requests is issued by client.

Change-Id: I83ac2000d860dfef5532910a2a73cd927b68e95f
Signed-off-by: Mona Hossain <mhossain@codeaurora.org>
Signed-off-by: Zhen Kong <zkong@codeaurora.org>