soc: renesas: r9a09g056-sys: Populate max_register

soc: renesas: r9a09g056-sys: Populate max_register

[ Upstream commit 4ff787433ba6d564b00334b4bfd6350f5b6f4bb3 ]

Populate max_register to avoid external aborts.

Fixes: 2da2740fb9c8 ("soc: renesas: rz-sysc: Add syscon/regmap support")
Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://patch.msgid.link/20251105070526.264445-2-claudiu.beznea.uj@bp.renesas.com
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Sasha Levin <sashal@kernel.org>