soc: renesas: Identify R-Car V4M

Add support for identifying the R-Car V4M (R8A779H0) SoC.

Signed-off-by: Duy Nguyen <duy.nguyen.rh@renesas.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Link: https://lore.kernel.org/r/31e06d055aec1bc70c3e9a02f9268bcfc72b2204.1706194617.git.geert+renesas@glider.be