qseecom: Check if ce clock is enabled before sending cmd to TZ

Make change to check if ce clock is enabled before sending command
to TZ, then to prevent data aborting if clock is not enabled for
TZ crypto operation.

CRs-Fixed: 726840
Change-Id: I55b5b10ad80e741c39f8cf411f67e6b83887f3bb
Signed-off-by: Zhen Kong <zkong@codeaurora.org>