interconnect: imx: Add a missing of_node_put after of_device_is_available

Add an 'of_node_put()' call when a tested device node is not available.

Fixes: f0d80485 ("interconnect: Add imx core driver")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/20201206121304.29381-1-christophe.jaillet@wanadoo.fr


Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>