media: rockchip: rga: remove size from rga_frame

media: rockchip: rga: remove size from rga_frame

The size member is only used for the mmu page table mapping.
Therefore avoid storing the value and instead only calculate it
in place. This also avoids the calculation entirely when an external
iommu is used.

Reviewed-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>
Signed-off-by: Sven Püschel <s.pueschel@pengutronix.de>
Signed-off-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>