ia64: fix compile without swiotlb

Some non-generic ia64 configs don't build swiotlb, and thus should not
pull in the generic non-coherent DMA infrastructure.

Fixes: 68c608345c ("swiotlb: remove dma_mark_clean")
Reported-by: Tony Luck <tony.luck@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/ia64/mm/init.c

@@ -67,6 +67,7 @@ __ia64_sync_icache_dcache (pte_t pte)
 	set_bit(PG_arch_1, &page->flags);	/* mark page as clean */
 }
 
+#ifdef CONFIG_SWIOTLB
 /*
  * Since DMA is i-cache coherent, any (complete) pages that were written via
  * DMA can be marked as "clean" so that lazy_mmu_prot_update() doesn't have to
@@ -81,6 +82,7 @@ void arch_sync_dma_for_cpu(struct device *dev, phys_addr_t paddr,
 		set_bit(PG_arch_1, &pfn_to_page(pfn)->flags);
 	} while (++pfn <= PHYS_PFN(paddr + size - 1));
 }
+#endif
 
 inline void
 ia64_set_rbs_bot (void)