arm64: dts: rockchip: rk3568: Add Radxa ROCK 3 Model A board support

arm64: dts: rockchip: rk3568: Add Radxa ROCK 3 Model A board support

Add Radxa ROCK 3 Model A support. sync rk3568-rock-3a.dts from Linux 6.2.0-rc7

Board Specifications
- Rockchip RK3568
- 2/4/8GB LPDDR4 3200MT/s
- eMMC socket, SD card slot
- GbE LAN
- PCIe 3.0/2.0
- M.2 Connector
- 3.5mm Audio jack with mic
- HDMI 2.0, MIPI DSI/CSI
- USB 3.0 Host/OTG, USB 2.0 Host
- 40-pin GPIO expansion ports
- USB Type C PD 2.0, 9V/2A, 12V/2A, 15V/2A, 20V/2A

Refer Linux commit <22a442e6586c>
("arm64: dts: rockchip: add basic dts for the radxa rock3 model a")

Signed-off-by: Akash Gajjar <gajjar04akash@gmail.com>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>