ucc_geth: Fix a bunch of sparse warnings

ucc_geth didn't have anything marked as __iomem.  It was also inconsistent
with its use of in/out accessors (using them sometimes, not using them other
times).  Cleaning this up cuts the warnings down from hundreds to just over a
dozen.

Signed-off-by: Andy Fleming <afleming@freescale.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>