arm64: dts: rockchip: Add dfi and dmc nodes to rk3399

These are required to support DDR DVFS on RK3399 platforms.

Change since Daniel's posting: reordered by unit address, per existing
style

Signed-off-by: Lin Huang <hl@rock-chips.com>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Signed-off-by: Gaël PORTAY <gael.portay@collabora.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Brian Norris <briannorris@chromium.org>
Link: https://lore.kernel.org/r/20220308110825.v4.11.Ie97993621975c5463d7928a8646f3737c9f2921d@changeid


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