clk: mvebu: ap-cpu-clk: Fix a memory leak in error handling paths

clk: mvebu: ap-cpu-clk: Fix a memory leak in error handling paths

If we exit the for_each_of_cpu_node loop early, the reference on the
current node must be decremented, otherwise there is a leak.

Fixes: f756e362d938 ("clk: mvebu: add CPU clock driver for Armada 7K/8K")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/545df946044fc1fc05a4217cdf0054be7a79e49e.1619161112.git.christophe.jaillet@wanadoo.fr
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>