ACPI: arm64: Move DMA setup operations out of IORT

Extract generic DMA setup code out of IORT, so it can be reused by VIOT.
Keep it in drivers/acpi/arm64 for now, since it could break x86
platforms that haven't run this code so far, if they have invalid
tables.

Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/20210618152059.1194210-2-jean-philippe@linaro.org
Signed-off-by: Joerg Roedel <jroedel@suse.de>