clk: renesas: r9a08g045: Add clock, reset and power domain support for the VBATTB IP

The Renesas RZ/G3S SoC has an IP named Battery Backup Function (VBATTB)
that generates the RTC clock. Add clock, reset and power domain support
for it.

Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/20240614071932.1014067-2-claudiu.beznea.uj@bp.renesas.com


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