aq(4) driver for Aquantia 1/2.5/5/10Gb/s PCIe ethernet adapters

aq(4) driver for Aquantia 1/2.5/5/10Gb/s PCIe ethernet adapters

Adds support for Aquantia AQC1xx family of PCIe ethernet adapters. This
driver supports 1Gbps through 10Gbps modes of operation based on the
hardware and media/switch capabilities.

The initial code was ported from NetBSD, with jmatthew@ finishing up
the Tx/Rx ring support and interrupt handler routine.

The driver only supports devices using firmware V2.

This diff enables aq(4) on riscv64 and amd64, the only platforms where
I have tested the driver, but it likely works on other architectures
as well.