ANDROID: GKI: iommu: Snapshot of vendor changes

Snapshot of IOMMU changes as of commit 79efc458af96.

Following files copied verbatim:
  arch/arm64/mm/dma-mapping.c
  drivers/iommu/dma-iommu.c
  drivers/iommu/io-pgtable.c
  drivers/iommu/iova.c
  include/linux/iova.h
  include/linux/dma-iommu.h
  include/linux/io-pgtable.h
  include/linux/iommu.h
  include/trace/events/iommu.h

Remainder contain targetted merged content:
  drivers/iommu/iommu.c
  include/linux/dma-mapping.h

Preserving Signed-off-bys from all the commits that touch these files.
Signed-off-by: Charan Teja Reddy <charante@codeaurora.org>
Signed-off-by: Liam Mark <lmark@codeaurora.org>
Signed-off-by: Mark Salyzyn <salyzyn@google.com>
Signed-off-by: Patrick Daly <pdaly@codeaurora.org>
Signed-off-by: Prakash Gupta <guptap@codeaurora.org>
Signed-off-by: Qingqing Zhou <qqzhou@codeaurora.org>
Signed-off-by: Rishabh Bhatnagar <rishabhb@codeaurora.org>
Signed-off-by: Shiraz Hashim <shashim@codeaurora.org>
Signed-off-by: Sudarshan Rajagopalan <sudaraja@codeaurora.org>
Signed-off-by: Swathi Sridhar <swatsrid@codeaurora.org>
Signed-off-by: Vijayanand Jitta <vjitta@codeaurora.org>
Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>

Bug: 155522481
Signed-off-by: Mark Salyzyn <salyzyn@google.com>
Change-Id: I8dcfb6b857547c512c56549085769eee59cabefb
[saravanak Deleted some dead code and split out some changes into
smaller commits]
Signed-off-by: Saravana Kannan <saravanak@google.com>