crypto:msm: fix compilation issue for crypto APIs

New APIs introduced as part of new FDE design can
not be referenced if driver config flag is not defined.
Provide a dummy reference to handle this case.

Change-Id: I7cfacd34ffca8cb156e3b12b6f29586950bf1ad8
Signed-off-by: Neeraj Soni <neersoni@codeaurora.org>