dt-bindings: clock: renesas: Document RZ/G3E SoC CPG

Document the device tree bindings for the Renesas RZ/G3E SoC
Clock Pulse Generator (CPG).

Also define constants for the core clocks of the RZ/G3E SoC.

Acked-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/20241203105005.103927-5-biju.das.jz@bp.renesas.com


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