clk: mv98dx3236: fix refcount leak in mv98dx3236_clk_init()

The of_find_compatible_node() returns a node pointer with refcount
incremented, but there is the lack of use of the of_node_put() when
done. Add the missing of_node_put() to release the refcount.

Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
Reviewed-by: Gregory CLEMENT <gregory.clement@bootlin.com>
Fixes: 33707260 ("clk: mvebu: Expand mv98dx3236-core-clock support")
Signed-off-by: Stephen Boyd <sboyd@kernel.org>