ARM: dts: rockchip: use DMA channels for UARTs for RK3288

This patch enables to use DMAC for all UARTs that are connected to
dmac_peri core for Rochchip RK3288.

Only uart2 is connected different DMAC (dmac_bus_s) so keep current
settings on this patch.

Signed-off-by: Katsuhiro Suzuki <katsuhiro@katsuster.net>
Link: https://lore.kernel.org/r/20200315095115.10106-1-katsuhiro@katsuster.net


Signed-off-by: Heiko Stuebner <heiko@sntech.de>