arm64: add support for NO_KERNEL_MAPPING and STRONGLY_ORDERED

arm64 needs support for both DMA_ATTR_NO_KERNEL_MAPPING and
DMA_ATTR_STRONGLY_ORDERD. Add support for both of them.

Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
[imaund@codeaurora.org: Resolved context conflicts]
Signed-off-by: Ian Maund <imaund@codeaurora.org>