of/irq: Fix device node refcount leakage in API of_irq_parse_raw()

of/irq: Fix device node refcount leakage in API of_irq_parse_raw()

if the node @out_irq->np got by of_irq_parse_raw() is a combo node which
consists of both controller and nexus, namely, of_irq_parse_raw() returns
due to condition (@ipar == @newpar), then the node's refcount was increased
twice, hence causes refcount leakage.

Fix by putting @out_irq->np refcount before returning due to the condition.
Also add comments about refcount of node @out_irq->np got by the API.

Fixes: 041284181226 ("of/irq: Allow matching of an interrupt-map local to an interrupt controller")
Cc: stable@vger.kernel.org
Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com>
Link: https://lore.kernel.org/r/20250209-of_irq_fix-v2-4-93e3a2659aa7@quicinc.com
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>