clk: davinci: pll: Add of_node_put() in of_davinci_pll_init()

clk: davinci: pll: Add of_node_put() in of_davinci_pll_init()

The variable child in the function of_davinci_pll_init takes the value
of of_get_child_by_name, which gets a node but does not put it. If child
is not put before the function returns it may cause a memory leak. Hence
put child before two return statements.
Issue found with Coccinelle.

Signed-off-by: Nishka Dasgupta <nishkadg.linux@gmail.com>
Link: https://lkml.kernel.org/r/20190804162824.6338-1-nishkadg.linux@gmail.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>