arm: rockchip: Add Radxa ROCK 4SE

Add board-specific devicetree/config for the RK3399T-based Radxa ROCK 4SE
board. This board offers similar peripherals in a similar form-factor to
the existing ROCK Pi 4B but uses the cost-optimised RK3399T processor
(which has different OPP table than the RK3399) and other minimal hardware
changes.

Kernel tag: next-20230719
Kernel commits:
- 86a0e14a82ea ("arm64: dts: rockchip: Add Radxa ROCK 4SE")

Signed-off-by: Christopher Obbard <chris.obbard@collabora.com>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>