Separate wait() and enumerate() methods from struct usbhost_driver_s and move to new interface, struct usbhost_connection_s.  This is part of the necessary restructuring of the USB host interface to support multiple root hub ports.

Add untested OHCI driver for the SAMA5; structure naming and header files for USB host initialization prototypes

SAMA5: Add PIO interrupt support.  Massive name changes for consistency in PIO vs GPIO naming.  SAMA5D3x-EK:  Add support for SD card detection PIO interrupts

SAMA5:  SPI Driver + AT25 FLASH work; SAM3/4:  Correct an error, SPI will not be correctly configured if CONFIG_SPI_OWNBUS=n

Standard configuration variables used to enable interupt controller debug; SAMA5: Correct handling of spurious interrupts

SAMA5: Change mapping of vector tables to work around that fact that I don't understand how the AXI MATRIX remap works

ARMv7-A:  Add cp15_disable_dcache(); SAMA5: nor_main.c no disables MMU and caches; Should not remap ISRAM to address 0x0 unless we booted into ISRAM

SAMA5: The ostest configuration have been converted to run out of NOR flash.  There is more to be done, however