dmaengine: sh: rz-dmac: fix device leak on probe failure

dmaengine: sh: rz-dmac: fix device leak on probe failure

Make sure to drop the reference taken when looking up the ICU device
during probe also on probe failures (e.g. probe deferral).

Fixes: 7de873201c44 ("dmaengine: sh: rz-dmac: Add RZ/V2H(P) support")
Cc: stable@vger.kernel.org	# 6.16
Cc: Fabrizio Castro <fabrizio.castro.jz@renesas.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Fabrizio Castro <fabrizio.castro.jz@renesas.com>
Link: https://patch.msgid.link/20251117161258.10679-10-johan@kernel.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>