clk: imx: composite-8m: remove round_rate() in favor of determine_rate()

clk: imx: composite-8m: remove round_rate() in favor of determine_rate()

This driver implements both the determine_rate() and round_rate() clk
ops, and the round_rate() clk ops is deprecated. When both are defined,
clk_core_determine_round_nolock() from the clk core will only use the
determine_rate() clk ops, so let's remove the round_rate() clk ops since
it's unused.

Signed-off-by: Brian Masney <bmasney@redhat.com>
Link: https://lore.kernel.org/r/20250710-clk-imx-round-rate-v1-1-5726f98e6d8d@redhat.com
Reviewed-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>