arm64: dma-mapping: remove order parameter from arm_iommu_create_mapping()

arm32 recently removed the `order' parameter from arm_iommu_create_mapping:
commit 68efd7d2 ("arm: dma-mapping: remove order parameter from
arm_iommu_create_mapping()") in order to make the API easier to understand.
The arm32 DMA IOMMU mapper has dynamic resizing of the iova bitmap, so
there was no reason to keep the `order' parameter around (which was
introduced to reduce the size of the bitmap).

Although we don't have dynamic iova bitmap reallocation on arm64, we'd
still like to get rid of the `order' parameter since it's confusing and
doesn't really help much (especially since all known clients on our
system are passing order=0).  Remove it.

Change-Id: I35e32fdfbe05ec434f64a3a316d13c8f43304bc6
Signed-off-by: Mitchel Humpherys <mitchelh@codeaurora.org>
[pdaly@codeaurora.org Remove gpu/ipa etc modifications]
Signed-off-by: Patrick Daly <pdaly@codeaurora.org>