The channel parameters (which are read from the device-tree) are adjusted
for the DMAEngine framework in the axi_dmac_parse_chan_dt() function, after
they are read from the device-tree.

When we want to read these from registers, we will need to use the same
logic, so this change splits the logic into a separate function.
Signed-off-by: NAlexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20200825151950.57605-6-alexandru.ardelean@analog.comSigned-off-by: NVinod Koul <vkoul@kernel.org>