Staging: unisys: uislib: Cleanup sparse warnings in uislib

Clean up code to get rid of sparse warnings, mostly related to accessing I/O
space.

Remove uislibcmpxchg64() and use cmpxchg() instead.

Signed-off-by: Ken Cox <jkc@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>