board: rockchip: add ArmSoM Sige7 Rk3588 board

board: rockchip: add ArmSoM Sige7 Rk3588 board

ArmSoM Sige7 is a Rockchip RK3588 based SBC (Single Board Computer) by
ArmSoM.

There are two variants depending on the DRAM size : 8G and 16G.

Specification:

    Rockchip Rk3588 SoC
    4x ARM Cortex-A76, 4x ARM Cortex-A55
    8/16GB memory LPDDR4x
    Mali G610MC4 GPU
    2x MIPI CSI 2 multiple lanes connector
    64GB/128GB on board eMMC
    uSD slot
    1x USB 2.0 Type-A, 1x USB 3.0 Type-A, 1x USB 3.0 Type-C
    1x HDMI 2.1 output
    2x 2.5 Gbps Ethernet port
    40-pin IO header including UART, SPI and I2C
    USB PD over USB Type-C
    Size: 92mm x 62mm

Kernel commit:
81c828a67c78 (arm64: dts: rockchip: Add ArmSom Sige7 board)

Signed-off-by: Jianfeng Liu <liujianfeng1994@gmail.com>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>