SAMA5 EMAC:  Resolve issues with DUAL PHY support needed for both EMAC and GMAC peripherals.  EMAC driver is now code complete and builds without complaint

SAMA5 EHCI:  Did not work with DEBUG off.  Appears to be because of some D-Cache flushing that was performed only with DEBUG ON.  Now is unconditional

USB MSC host class driver: Don't bother retrying to initialize the FLASH if the interface is returning fatal transfer errors

SAMA5:  Add support EHCI/OHCI to sama5d3x-ek/demo (does not work yet); Fix some EHCI/OHCI compilation issues when DEBUG is disabled

CDC/ACM and PL2303 device drivers:  Don't use the max packet size assigned to an endpoint in order to determine the request buffer size.  The endpoint has not yet been configured that max packet size may be wrong.