Add support to program the ATU to enable translations for >4GB sizes of
the prefetchable memory apertures.

Link: https://lore.kernel.org/r/20201118144626.32189-3-vidyas@nvidia.comTested-by: NThierry Reding <treding@nvidia.com>
Tested-by: NJon Hunter <jonathanh@nvidia.com>
Signed-off-by: NVidya Sagar <vidyas@nvidia.com>
Signed-off-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: NRob Herring <robh@kernel.org>
Acked-by: NJingoo <jingoohan1@gmail.com>