Reinstate Ethernet BSP Autogeneration

[ztnel]

Description

Due to the tight coupling between the ethernet interface source code for LWIP and the ethernet low level drivers, I have chose to exclude the ethernet module generation from the BSP:

The code for ethernet hardware configuration is handled by ethernetif.c in the application core. This means changes made to the ETH module in CubeMX will have not have any effect on the project build. It is important to ensure the hardware configuration is visible and in lockstep with the IOC file. This requires decoupling of the hardware configuration functions from LWIP specific functionality in ethernetif.c.