[IA64] sparse cleanups

Fix some sparse warnings on ia64.  Large constants that should be long
instead of int.  Use NULL instead of 0.  Add some missing __iomem
casts.  Replace a non-C99 structure assignment.

Signed-off-by: Keith Owens <kaos@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>