[IA64] sim: Add casts to avoid assignment warnings

Pointers in the efi_runtime_services_t structure now have type
"void *" (formerly they were "unsigned long"). So we now see a
bunch of warnings like this:

arch/ia64/hp/sim/boot/fw-emu.c:293: warning: assignment makes pointer from integer without a cast

Add (void *) casts to the 10 affected lines to make the build quiet again.

Signed-off-by: Tony Luck <tony.luck@intel.com>