clk: imx: Fix PLL_1416X not rounding rates

Code which initializes the "clk_init_data.ops" checks pll->rate_table
before that field is ever assigned to so it always picks
"clk_pll1416x_min_ops".

This breaks dynamic rate rounding for features such as cpufreq.

Fix by checking pll_clk->rate_table instead, here pll_clk refers to
the constant initialization data coming from per-soc clk driver.

Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
Fixes: 8646d4dc ("clk: imx: Add PLLs driver for imx8mm soc")
Signed-off-by: Stephen Boyd <sboyd@kernel.org>