SAMV7:  Add a sneak internal interface that will allow us to set the MAC address before NSH even starts

SAMV7: Updates to Ethernet driver based on comparison with Atmel sample code.  Add configuration for other PHY GPIOs.  Still no Ethernet interrupts

PIC32MZ: Changes that will permit building of the PIC32MZ Start Kit configuration using MPLAB and the XC32 toolchain.  From David Sidrane