usbdebug: Add option for verbose logging of connection

Add option to log changes in USB 2.0 EHCI debug port connection.
For romstage move usbdebug as the last initialised console so one
actually can see these messages.

Init order of consoles in ramstage is undetermined and unchanged.

Change-Id: I3aceec8a93064bd952886839569e9f5beb6c5720
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: http://review.coreboot.org/3387
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@google.com>

src/lib/usbdebug.c

@@ -57,19 +57,12 @@ struct ehci_debug_info {
 	struct dbgp_pipe ep_pipe[DBGP_MAX_ENDPOINTS];
 };
 
-/* Set this to 1 to debug the start-up of EHCI debug port hardware. You need
- * to modify console_init() to initialise some other console before usbdebug
- * to receive the printk lines from here.
- * There will be no real usbdebug console output while DBGP_DEBUG is set.
- */
-#define DBGP_DEBUG 0
-#if DBGP_DEBUG
+#if CONFIG_DEBUG_USBDEBUG
 # define dbgp_printk(fmt_arg...) printk(BIOS_DEBUG, fmt_arg)
 #else
-#define dbgp_printk(fmt_arg...)   do {} while(0)
+# define dbgp_printk(fmt_arg...)   do {} while(0)
 #endif
 
-
 #define USB_DEBUG_DEVNUM 127
 
 #define DBGP_DATA_TOGGLE	0x8800