dt-bindings: clock: renesas,rzg2l: Document RZ/Five SoC

dt-bindings: clock: renesas,rzg2l: Document RZ/Five SoC

The CPG block on the RZ/Five SoC is almost identical to one found on the
RZ/G2UL SoC. "renesas,r9a07g043-cpg" compatible string will be used on
the RZ/Five SoC so to make this clear, update the comment to include
RZ/Five SoC.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Link: https://lore.kernel.org/r/20220726174525.620-1-prabhakar.mahadev-lad.rj@bp.renesas.com
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>