clk: renesas: rzg2l: Add divider clock for RZ/G3S

clk: renesas: rzg2l: Add divider clock for RZ/G3S

Add a divider clock driver for RZ/G3S.  This will be used on RZ/G3S for
the SDHI, SPI, OCTA, I, I2, I3, P0, P1, P2, and P3 core clocks.
The divider has some limitation for SDHI, OCTA and SPI clocks:
  - SDHI div cannot be 1 if parent rate is 800MHz,
  - OCTA, SPI div cannot be 1 if parent rate is 400MHz.
To handle these limitations, a notifier is registered from platform
specific clock driver, which makes sure proper actions are taken before
the clock rate is changed, when needed.

Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20231006103959.197485-4-claudiu.beznea.uj@bp.renesas.com
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>