ARM: dts: at91: Enable DMA on sama5d4_xplained console

ARM: dts: at91: Enable DMA on sama5d4_xplained console

commit ef8d02d4a2c36f7a93e74c95a9c419353b310117 upstream.

Enable DMA on usart3 to get a more reliable console. This is especially
useful for automation and kernelci were a kernel with PROVE_LOCKING enabled
is quite susceptible to character loss, resulting in tests failure.

Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>