Move platform device creation earlier in the initialization

Some logs are printed out early using smi->dev, but on a platform device
that is not created until later.  So move the creation of that device
structure earlier in the sequence so it can be used for printing.

Signed-off-by: Corey Minyard <cminyard@mvista.com>
Tested-by: Corentin Labbe <clabbe.montjoie@gmail.com>