cqhci: Set the supported dun size

Driver need to register the supported data unit number (dun) size
with keyslot manager so that encryption request with unsupported
dun size can fallback to fs or block crypto.

Change-Id: I9ecaea0610b7444fd165a71d03563608248db8c1
Signed-off-by: Neeraj Soni <neersoni@codeaurora.org>