clk: keystone: Fix discarded const qualifiers

Add const qualifiers to the pointers returned from 'container_of' macro
to prevent breaking the const promise on const struct pointers from
parameters.

Once you have a mutable container structure pointer, you can change
structure fields through it, which violates the const guarantee.

Signed-off-by: Adrian Barnaś <abarnas@google.com>
Reviewed-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

Author: abarnas-usys

drivers/clk/keystone/sci-clk.c

@@ -496,8 +496,8 @@ static int ti_sci_scan_clocks_from_fw(struct sci_clk_provider *provider)
 static int _cmp_sci_clk_list(void *priv, const struct list_head *a,
 			     const struct list_head *b)
 {
-	struct sci_clk *ca = container_of(a, struct sci_clk, node);
-	struct sci_clk *cb = container_of(b, struct sci_clk, node);
+	const struct sci_clk *ca = container_of(a, struct sci_clk, node);
+	const struct sci_clk *cb = container_of(b, struct sci_clk, node);
 
 	return _cmp_sci_clk(ca, &cb);
 }