net: airoha: Add the capability to consume out-of-order DMA tx descriptors

net: airoha: Add the capability to consume out-of-order DMA tx descriptors

EN7581 and AN7583 SoCs are capable of DMA mapping non-linear tx skbs on
non-consecutive DMA descriptors. This feature is useful when multiple
flows are queued on the same hw tx queue since it allows to fully utilize
the available tx DMA descriptors and to avoid the starvation of
high-priority flow we have in the current codebase due to head-of-line
blocking introduced by low-priority flows.

Tested-by: Xuegang Lu <xuegang.lu@airoha.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://patch.msgid.link/20251106-airoha-tx-linked-list-v2-1-0706d4a322bd@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>