clk: at91: pmc: decrement node's refcount

of_find_matching_node() increment node's refcount. Call
of_node_put() to decrement it after it was used.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lkml.kernel.org/r/1588508289-10140-2-git-send-email-claudiu.beznea@microchip.com


Signed-off-by: Stephen Boyd <sboyd@kernel.org>