clk: renesas: rcar-gen4: Add support for fractional 9.24 PLLs

The custom clock driver that models the PLL clocks on R-Car Gen4
supports only fractional 8.25 PLLs, as used on R-Car V4H/V4M.
R-Car S4-8 uses integer and fractional multiplication fields that are
one bit larger resp. smaller, and a slightly different formula.

Extend the existing support to fractional 9.24 PLL, and introduce new
clock types and helper macros to describe these PLLs.

Note that there is no use case for variable fractional 9.24 PLLs yet, as
the Cortex-A55 cores on R-Car S4-8 do not support High Performance mode.
Hence the PLL is always modeled as a fixed PLL, regardless of the
description,

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Link: https://lore.kernel.org/5684eda1260435c8eceabc274e0b18cb280a6341.1721648548.git.geert+renesas@glider.be