* The driver structure is almost the same as in the STM32 Ethernet driver.
* The PHY autodetection code was copied from the STM32 Ethernet driver
    (see `lpc178x_phy_init()`)
* The speed/duplex detection logic grabbed from the Linux kernel
    (see linux/drivers/net/phy/phy_device.c)
* The DMA used for Ethernet cannot work with the SoC-internal "System
    RAM", thus we use the external memory (SDRAM) for DMA descriptors
    and buffers.