powerpc/mm: Drop the 64K on 4K version of pte_pagesize_index()

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: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>

arch/powerpc/include/asm/pgtable-ppc64.h

@@ -134,23 +134,11 @@
 
 #define pte_iterate_hashed_end() } while(0)
 
-#ifdef CONFIG_PPC_HAS_HASH_64K
 /*
  * We expect this to be called only for user addresses or kernel virtual
  * addresses other than the linear mapping.
  */
-#define pte_pagesize_index(mm, addr, pte)			\
-	({							\
-		unsigned int psize;				\
-		if (is_kernel_addr(addr))			\
-			psize = MMU_PAGE_4K;			\
-		else						\
-			psize = get_slice_psize(mm, addr);	\
-		psize;						\
-	})
-#else
 #define pte_pagesize_index(mm, addr, pte)	MMU_PAGE_4K
-#endif
 
 #endif /* __real_pte */