The DMA API has the notion of buffer ownership; make it explicit in the
ARM implementation of this API.  This gives us a set of hooks to allow
us to deal with CPU cache issues arising from non-cache coherent DMA.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Tested-By: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Tested-By: NJamie Iles <jamie@jamieiles.com>