Add initial support for the Renesas R8A77990 (R-Car V3U) support.
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Link: https://lore.kernel.org/r/1599739372-30669-4-git-send-email-yoshihiro.shimoda.uh@renesas.comSigned-off-by: Geert Uytterhoeven <geert+renesas@glider.be>