The peripheral bus on the i.MX8MQ is still limited to 32bits, so
we need to declare the usable range for device DMA operations, as
the DRAM will extend across the 32bit boundary if more than 3GB
are installed.
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>