clk: meson: axg-audio: setup regmap max_register based on the SoC

The register region of axg-audio tends to grow with the addition of
new supported SoC. Mapping slightly more has not been causing problem
so far but it is not viable to continue like this long term.

Setup the max register based on what is necessary on the related SoC.

Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://lore.kernel.org/r/20240719093934.3985139-3-jbrunet@baylibre.com


Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>