soc: renesas: Identify R-Car S4-8

Add support for identifying the R-Car S4-8 (R8A779F0) SoC.

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Link: https://lore.kernel.org/r/20211201073308.1003945-8-yoshihiro.shimoda.uh@renesas.com


Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>