icnss: Make driver register asynchronous to probe

Driver register doesn't have to be synchronous with probe call
back. Keep the driver registered till unregister gets called and
never reset ops during probe failure.

CRs-fixed: 2029329
Change-Id: I61331c7f33b29b0bc4833a8e4c52ee94f17660e7
Signed-off-by: Anurag Chouhan <achouhan@codeaurora.org>