clk: imx: composite-8m: Add support to determine_rate

Similar to imx/clk-composite-93 and imx/clk-divider-gate, the
imx8m_clk_composite_divider_ops can support determine_rate.
Without this the parent clocks are set to a fixed value, and
if a consumer needs a slower reate, the clock is divided, but
the division is only as good as the parent clock rate.

With this added, the system can attempt to adjust the parent rate
if the proper flags are set which can lead to a more precise clock
value.

Signed-off-by: Adam Ford <aford173@gmail.com>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
Reviewed-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Abel Vesa <abel.vesa@linaro.org>
Link: https://lore.kernel.org/r/20230323230127.120883-2-aford173@gmail.com