[IA64] fix ia64 Kconfig to allow CONFIG_PM on sn2

This probably should have been fixed when I fixed up the generic build for
discontig+numa machines, but oh well.

CONFIG_PM is allowable for generic builds but not for sn2 builds, which
doesn't make much sense, and in fact breaks the build if recent ACPI bits are
added to the tree.  It looks like the only arch that needs to prevent
CONFIG_PM stuff is the ski simulator (though those options could probably use
some cleanup as well), so remove the big conditional and replace it with a
simple test for IA64_HP_SIM instead.
Signed-off-by: NJesse Barnes <jbarnes@sgi.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!