dmaengine: ti: dma-crossbar: fix device leak on am335x route allocation

dmaengine: ti: dma-crossbar: fix device leak on am335x route allocation

Make sure to drop the reference taken when looking up the crossbar
platform device during am335x route allocation.

Fixes: 42dbdcc6bf96 ("dmaengine: ti-dma-crossbar: Add support for crossbar on AM33xx/AM43xx")
Cc: stable@vger.kernel.org	# 4.4
Cc: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://patch.msgid.link/20251117161258.10679-15-johan@kernel.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>