clk: renesas: rzg2l: Postpone updating priv->clks[]

Since the sibling data is filled after the priv->clks[] array entry is
populated, the first clock that is probed and has a sibling will
temporarily behave as its own sibling until its actual sibling is
populated. To avoid any issues, postpone updating priv->clks[] until after
the sibling is populated.

Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/20250514090415.4098534-2-claudiu.beznea.uj@bp.renesas.com


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