misc ia64 cleanups (resend)

A couple random cleanups I stumbled upon when doing dma related work.

Follow-Ups:
- [PATCH 9/9] intel-iommu: mark intel_dma_ops static
  - From: Christoph Hellwig
- [PATCH 8/9] ia64: remove machvec_dma_sync_{single,sg}
  - From: Christoph Hellwig
- [PATCH 7/9] ia64/sn2: remove no-ops dma sync methods
  - From: Christoph Hellwig
- [PATCH 6/9] ia64: remove the unused iommu_dma_init function
  - From: Christoph Hellwig
- [PATCH 5/9] ia64: remove the unused pci_iommu_shutdown function
  - From: Christoph Hellwig
- [PATCH 4/9] ia64: remove the unused bad_dma_address symbol
  - From: Christoph Hellwig
- [PATCH 3/9] ia64: remove iommu_dma_supported
  - From: Christoph Hellwig
- [PATCH 2/9] ia64: remove the dead iommu_sac_force variable
  - From: Christoph Hellwig
- [PATCH 1/9] ia64: remove the kern_mem_attribute export
  - From: Christoph Hellwig