net: dsa: mv88e6xxx: introduce .serdes_irq_mapping

Introduce a new .serdes_irq_mapping operation to prepare the
abstraction of IRQ mapping from the SERDES IRQ setup code.

Signed-off-by: Vivien Didelot <vivien.didelot@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
4 files changed