clk: Mark clk_core_evict_parent_cache_subtree() 'target' const

Clarify that the 'target' clk isn't being modified, instead it's being
searched for. Mark it const so the function can't modify it.
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lore.kernel.org/r/20220217220554.2711696-3-sboyd@kernel.org

drivers/clk/clk.c

@@ -4079,7 +4079,7 @@ static const struct clk_ops clk_nodrv_ops = {
 };
 
 static void clk_core_evict_parent_cache_subtree(struct clk_core *root,
-						struct clk_core *target)
+						const struct clk_core *target)
 {
 	int i;
 	struct clk_core *child;