usbdebug: Move under drivers/usb

Also relocate and split header files, there is some interest
for EHCI debug support without PCI.

Change-Id: Ibe91730eb72dfe0634fb38bdd184043495e2fb08
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: http://review.coreboot.org/5129
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@google.com>

src/include/console/console.h

@@ -28,7 +28,7 @@
 #include <uart.h>
 #endif
 #if CONFIG_USBDEBUG && !defined(__ROMCC__)
-#include <usbdebug.h>
+#include <console/usb.h>
 #endif
 #if CONFIG_CONSOLE_NE2K
 #include <console/ne2k.h>