dt-bindings: riscv: Add StarFive JH7110 SoC and VisionFive 2 board

Add device tree bindings for the StarFive JH7110 RISC-V SoC
and the VisionFive 2 board equipped with it.

VisionFive 2 board has version A and version B, which are
different in gmac and phy chip. The version A board has one
1000Mbps and one 100Mbps Ethernet ports while the version B
board has two 1000Mbps Ethernet ports.

Link: https://doc-en.rvspace.org/Doc_Center/jh7110.html
Link: https://doc-en.rvspace.org/Doc_Center/visionfive_2.html


Signed-off-by: Emil Renner Berthing <kernel@esmil.dk>
Signed-off-by: Hal Feng <hal.feng@starfivetech.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>