Now that support for 64k pages with a 4K kernel is removed, this code is
unreachable.

CONFIG_PPC_HAS_HASH_64K can only be true when CONFIG_PPC_64K_PAGES is
also true.

But when CONFIG_PPC_64K_PAGES is true we include pte-hash64.h which
includes pte-hash64-64k.h, which defines both pte_pagesize_index() and
crucially __real_pte, which means this definition can never be used.
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Reviewed-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>