security: pfe: Disable clocks for crypto engine

Even if invalidate key scm call is failed crypto
engine clocks should be disabled as fresh set key
call will any way enable clocks again. This will
also help in power savings.

Change-Id: I640150228112a3d36f49cb52a7de0df6cc6a4662
Signed-off-by: Neeraj Soni <neersoni@codeaurora.org>