Add ENCX24J600 Ethernet driver and support for the ENCX24J600 with the Olimex STM32 P107 board.  From Max Holtberg

SAMA5 OHCI:  Fix semaphore handling bug.  OHCI is now function by itself again after changes to integrate with EHCI

SAMA5: EHCI now handles low- and full-speed connections by giving them to OHCI; OHCI now uses the work queue to defer interrupt processing; If both OHCI and EHCI are enabled, EHCI is the master of the UHPHS interrupt

SAMA5/ECHI:  Debug register access, add logic to determine transfer size, fix setting of control bit in token

SAMA5 OHCI:  Re-organize some endpoint list data structures.. Strange things happen when semaphores lie in DMA memory which is occasionally invalidated