rockchip: rk3368: sync main rk3368 dtsi from Linux

This is the state as of v5.10 + the recently added timer0 phandle
targetted at the 5.12 merge window.

With this the non-mainline nodes like the dmc move to a separate
rk3368-u-boot.dtsi that is included from the board-specific
-u-boot.dtsi files, similar to how rk3399 does this.

Signed-off-by: Heiko Stuebner <heiko.stuebner@theobroma-systems.com>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>