ANDROID: GKI: drivers: Add dma removed ops

The current DMA coherent pool assumes that there is a kernel
mapping at all times for the entire pool. This may not be
what we want for the entire times. Add the dma_removed ops to
support this use case.

Bug: 145617272
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
Signed-off-by: Patrick Daly <pdaly@codeaurora.org>
Signed-off-by: Liam Mark <lmark@codeaurora.org>
Signed-off-by: Swathi Sridhar <swatsrid@codeaurora.org>

[surenb Squashed the following commits:
a478a8bf "drivers: Add dma removed ops"
8510985a "dma: removed: Merge dma removed changes from 4.14"
and removed-dma-pool driver changes from
9d4b7d64 "iommu: arm-smmu: Merge for ..."]

Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Change-Id: Ie4f1e9bdf57b79699fa8fa7e7a6087e6d88ebbfa