net: airoha: Add airoha_qdma pointer in airoha_tx_irq_queue/airoha_queue structures

Move airoha_eth pointer in airoha_qdma structure from
airoha_tx_irq_queue/airoha_queue ones. This is a preliminary patch to
introduce support for multi-QDMA controllers available on EN7581.

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://patch.msgid.link/074565b82fd0ceefe66e186f21133d825dbd48eb.1722522582.git.lorenzo@kernel.org


Signed-off-by: Jakub Kicinski <kuba@kernel.org>