clk: sunxi-ng: nkm: Prefer current parent rate

Similar to ccu_mp, if the current parent rate allows getting the ideal
rate, prefer to not change the parent clock's rate.

Reviewed-by: Jernej Skrabec <[email protected]>
Signed-off-by: Frank Oltmanns <[email protected]>
Link: https://lore.kernel.org/r/20230807-pll-mipi_set_rate_parent-v6-11-f173239a4b59@oltmanns.dev
Signed-off-by: Chen-Yu Tsai <[email protected]>

Author: Frank Oltmanns

drivers/clk/sunxi-ng/ccu_nkm.c

@@ -34,7 +34,8 @@ static unsigned long ccu_nkm_find_best_with_parent_adj(struct ccu_common *common
 
 				tmp_rate = tmp_parent * _n * _k / _m;
 
-				if (ccu_is_better_rate(common, rate, tmp_rate, best_rate)) {
+				if (ccu_is_better_rate(common, rate, tmp_rate, best_rate) ||
+				    (tmp_parent == *parent && tmp_rate == best_rate)) {
 					best_rate = tmp_rate;
 					best_parent_rate = tmp_parent;
 					best_n = _n;