Revert "[IA64] fix percpu warnings"

This reverts commit b94b08081fcecf83fa690d6c5664f6316fe72208.

genksyms currently cannot handle complicated types for exported
percpu variables.  Drop this patch for now as it prevents a
module from being loaded on sn2 systems:

 xpc: no symbol version for per_cpu____sn_cnodeid_to_nasid
 xpc: Unknown symbol per_cpu____sn_cnodeid_to_nasid

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