dma-mapping: move dma configuration to bus infrastructure

ACPI/OF support for configuration of DMA is a bus specific aspect, and
thus should be configured by the bus.  Introduces a 'dma_configure' bus
method so that busses can control their DMA capabilities.

Also update the PCI, Platform, ACPI and host1x buses to use the new
method.

Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nipun Gupta <nipun.gupta@nxp.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>  # PCI parts
Acked-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[hch: simplified host1x_dma_configure based on a comment from Thierry,
      rewrote changelog]
Signed-off-by: Christoph Hellwig <hch@lst.de>
7 files changed