[IA64] remove asm-ia64/bitops.h self-inclusion

asm-ia64/bitops.h includes itself.  The #ifndef _ASM_IA64_BITOPS_H
prevents this from being an issue, but it should still be removed.

Signed-off-by: Jon Mason <jdmason@us.ibm.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>