clk: renesas: rzg2l: Add macro to loop through module clocks

clk: renesas: rzg2l: Add macro to loop through module clocks

Add a macro to iterate over the module clocks array. This will be useful
in the upcoming commits that move MSTOP support into the clock
enable/disable APIs.

Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Link: https://lore.kernel.org/20250527112403.1254122-4-claudiu.beznea.uj@bp.renesas.com
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>