Add EHCI header file (not quite complete)

ChangeLog

@@ -5413,4 +5413,5 @@
 	  (2013-8-16)
 	* arch/arm/src/sama5/sam_ohci.c:  More to be tested, but the SAMA5
 	  OHCI driver is now basically funtional (2013-8-16).
+	* include/nuttx/usb/ehci.h:  EHCI header file (2013-8-17).
 

arch/arm/src/sama5/sam_ohci.c

@@ -2569,7 +2569,7 @@ static int sam_free(FAR struct usbhost_driver_s *drvr, FAR uint8_t *buffer)
  *   Some hardware supports special memory in which larger IO buffers can
  *   be accessed more efficiently.  This method provides a mechanism to allocate
  *   the request/descriptor memory.  If the underlying hardware does not support
- *   such "special" memory, this functions may simply map to kmalloc.
+ *   such "special" memory, this functions may simply map to kumalloc.
  *
  *   This interface differs from DRVR_ALLOC in that the buffers are variable-sized.
  *
@@ -2607,7 +2607,7 @@ static int sam_ioalloc(FAR struct usbhost_driver_s *drvr, FAR uint8_t **buffer,
  *   Some hardware supports special memory in which IO data can  be accessed more
  *   efficiently.  This method provides a mechanism to free that IO buffer
  *   memory.  If the underlying hardware does not support such "special" memory,
- *   this functions may simply map to kfree().
+ *   this functions may simply map to kufree().
  *
  * Input Parameters:
  *   drvr - The USB host driver instance obtained as a parameter from the call to