soc: renesas: rcar-sysc: Add r8a774b1 support

Add support for RZ/G2N (R8A774B1) SoC power areas to the R-Car SYSC
driver.

Signed-off-by: Biju Das <biju.das@bp.renesas.com>
Link: https://lore.kernel.org/r/1569223780-54304-1-git-send-email-biju.das@bp.renesas.com


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