boards: starfive: add visionfive2 board

these list of patches add support the Starfive Visionfive2
SBC based on the JH7110 SoC. Board identifier is `visionfive2`.

Signed-off-by: Kanak Shilledar <kanakshilledar111@protonmail.com>
Signed-off-by: Pratik Farkase <pratik.farkase@wsisweden.com>