board: rockchip: add FriendlyElec NanoPC-T6 rk3588 board

board: rockchip: add FriendlyElec NanoPC-T6 rk3588 board

The NanoPC-T6 is a Rockchip RK3588 based SBC by FriendlyElec.

There are four variants depending on the DRAM size: 4G/32GB eMMC,
8G/64GB eMMC, 16G/16MB SPI NOR, and 16G/256GB eMMC/16MB SPI NOR

Specifications:
    CPU: Rockchip RK3588, 4x Cortex-A76 (up to 2.4GHz)
                        + 4x Cortex-A55 (up to 1.8GHz)
    GPU: Mali-G610 MP4
    VPU: 8K@60fps H.265 and VP9 decoder, 8K@30fps H.264 decoder,
         4K@60fps AV1 decoder, 8K@30fps H.264 and H.265 encoder
    NPU: 6TOPs, supports INT4/INT8/INT16/FP16
    RAM: 64-bit 4GB/8GB/16GB LPDDR4X at 2133MHz
    eMMC: 0GB/32GB/64GB/256GB HS400
    MicroSD Slot: MicroSD SDR104
    PCIe 3.0: M.2 M-Key x1, PCIe 3.0 x4 for NVMe SSDs up to 2,500 MB/s
    Ethernet: PCIe 2.5G 2x Ethernet (RTL8125BG)
    PCIe 2.1: M.2 E-Key x1, PCIe 2.1 x1 and USB2.0 Host,
              supports M.2 WiFi and Bluetooth
    4G Module: MiniPCIe x1, MicroSIM Card Slot x1
    Audio Out: 3.5mm jack for stereo headphone output
    Audio In: 2.0mm PH-2A connector for analog microphone input
    Video Input: standard HDMI input port, up to 4Kp60
    2x 4-lane MIPI-CSI, compatible with MIPI V1.2
    Video Output: 2x standard HDMI output ports compatible with HDMI2.1,
                  HDMI2.0, and HDMI1.4
    2x 4-lane MIPI-DSI, compatible with MIPI DPHY 2.0 or CPHY 1.1
    USB-A: USB 3.0, Type A
    USB-C: Full function USB Type‑C port, DP display up to 4Kp60, USB 3.0
    40-pin 2.54mm header connector: up to 2x SPIs, 6x UARTs, 1x I2Cs,
                                    8x PWMs, 2x I2Ss, 28x GPIOs
    Debug UART: 3 Pin 2.54mm header, 3V level, 1500000bps
    Onboard IR receiver: 38KHz carrier frequency
    RTC Battery: 2 Pin 1.27/1.25mm RTC battery connector for low power
                 RTC IC HYM8563TS
    5V Fan connector
    Working Temperature: 0C to 70C
    Power: 5.5*2.1mm DC Jack, 12VDC input
    Dimensions: 110x80x1.6mm (without case) / 86x114.5x30mm (with case)

Kernel commits:
893c17716d0c ("arm64: dts: rockchip: Add NanoPC T6")
a721e28dfad2 ("arm64: dts: rockchip: Add NanoPC T6 PCIe Ethernet support")
ac76b786cc37 ("arm64: dts: rockchip: Add NanoPC T6 PCIe e-key support")

Signed-off-by: John Clark <inindev@gmail.com>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>