clk: rockchip: fix error for unknown clocks

There is a clk == NULL check after the switch to check for
unsupported clk types. Since clk is re-assigned in a loop,
this check is useless right now for anything but the first
round. Let's fix this up by assigning clk = NULL in the
loop before the switch statement.

Fixes: a245fec ("clk: rockchip: add basic infrastructure for clock branches")
Cc: stable@vger.kernel.org
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
[added fixes + stable-cc]
Link: https://lore.kernel.org/r/20240325193609.237182-6-sebastian.reichel@collabora.com
Signed-off-by: Heiko Stuebner <heiko@sntech.de>

Author: sre

drivers/clk/rockchip/clk.c

@@ -450,12 +450,13 @@ void rockchip_clk_register_branches(struct rockchip_clk_provider *ctx,
 				    struct rockchip_clk_branch *list,
 				    unsigned int nr_clk)
 {
-	struct clk *clk = NULL;
+	struct clk *clk;
 	unsigned int idx;
 	unsigned long flags;
 
 	for (idx = 0; idx < nr_clk; idx++, list++) {
 		flags = list->flags;
+		clk = NULL;
 
 		/* catch simple muxes */
 		switch (list->branch_type) {