clk: at91: keep securam node alive while mapping it

pmc_register_ops() gets an owned reference to the
"atmel,sama5d2-securam" node with of_find_compatible_node().  The
success path dropped that reference before passing the node to
of_iomap(), leaving of_iomap() to consume a node pointer after the caller
had released its reference.

Move of_node_put() after of_iomap() so the node remains referenced for
the mapping operation.  The unavailable-node error path already releases
the reference.

Fixes: 4d21be8 ("clk: at91: pmc: execute suspend/resume only for backup mode")
Signed-off-by: Yuho Choi <dbgh9129@gmail.com>
Reviewed-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://patch.msgid.link/20260529042051.1626978-1-dbgh9129@gmail.com
Signed-off-by: Claudiu Beznea <claudiu.beznea@tuxon.dev>

Author: Uuuuuuho

drivers/clk/at91/pmc.c

@@ -180,9 +180,9 @@ static int __init pmc_register_ops(void)
 		of_node_put(np);
 		return -ENODEV;
 	}
-	of_node_put(np);
 
 	at91_pmc_backup_suspend = of_iomap(np, 0);
+	of_node_put(np);
 	if (!at91_pmc_backup_suspend) {
 		pr_warn("%s(): unable to map securam\n", __func__);
 		return -ENOMEM;