net: ethernet: mtk_eth_wed: add mtk_wed_configure_irq and mtk_wed_dma_{enable/disable}

Introduce mtk_wed_configure_irq, mtk_wed_dma_enable and mtk_wed_dma_disable
utility routines.
This is a preliminary patch to introduce mt7986 wed support.

Tested-by: Daniel Golle <daniel@makrotopia.org>
Co-developed-by: Bo Jiao <Bo.Jiao@mediatek.com>
Signed-off-by: Bo Jiao <Bo.Jiao@mediatek.com>
Co-developed-by: Sujuan Chen <sujuan.chen@mediatek.com>
Signed-off-by: Sujuan Chen <sujuan.chen@mediatek.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>