net: airoha: Move entries to queue head in case of DMA mapping failure in airoha_dev_...

net: airoha: Move entries to queue head in case of DMA mapping failure in airoha_dev_xmit()

In order to respect the original descriptor order and avoid any
potential IOMMU fault or memory corruption, move pending queue entries
to the head of hw queue tx_list if the DMA mapping of current inflight
packet fails in airoha_dev_xmit routine.

Fixes: 3f47e67dff1f7 ("net: airoha: Add the capability to consume out-of-order DMA tx descriptors")
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://patch.msgid.link/20260429-airoha-xmit-unmap-error-path-v2-1-32e43b7c6d25@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>