arm64: defconfig: Enable VBATTB clock and Renesas RTCA-3

Enable the Renesas VBATTB clock and RTCA-3 RTC drivers.  These are
available on the Renesas RZ/G3S SoC.  VBATTB is the clock provider for
the RTC counter.

Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Link: https://lore.kernel.org/20241101095720.2247815-10-claudiu.beznea.uj@bp.renesas.com


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