arm64: dts: rockchip: add mipi_dsi1 support for rk3399

This patch adds the information for the secondary MIPI DSI controller,
e.g., interrupts, grf, clocks, ports and so on. Mirrors the existing
definition for dsi0.

Signed-off-by: Nickey Yang <nickey.yang@rock-chips.com>
Signed-off-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>