dmaengine: axi-dmac: extend support for ZynqMP arch

The AXI DMAC driver is currently supported also on the Xilinx ZynqMP
architecture. This change allows this driver to be enabled & used on it as
well.

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: Vinod Koul <vkoul@kernel.org>