Fix usb debug dongle support

- move enable_usbdebug() declaration to usbdebug.h
- reinitialize debug driver in ramstage, as copying the data
  structure from romstage doesn't work right now. This way of copying
  data from romstage to ramstage is really board/cpu specific, and is
  likely to break often. So don't do it.

Change-Id: I394678ded6679c1803e29eb691b926182bdcab68
Signed-off-by: Sven Schnelle <svens@stackframe.org>
Reviewed-on: http://review.coreboot.org/355
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>

src/southbridge/intel/i82801gx/Makefile.inc

@@ -38,4 +38,6 @@ smm-$(CONFIG_HAVE_SMI_HANDLER) += smihandler.c
 
 romstage-y += early_smbus.c
 romstage-$(CONFIG_USBDEBUG) += usb_debug.c
+ramstage-$(CONFIG_USBDEBUG) += usb_debug.c
+smm-$(CONFIG_USBDEBUG) += usb_debug.c
 

src/southbridge/intel/i82801gx/i82801gx.h

@@ -46,7 +46,6 @@ extern void i82801gx_enable(device_t dev);
 void enable_smbus(void);
 int smbus_read_byte(unsigned device, unsigned address);
 #endif
-void enable_usbdebug(unsigned int port);
 #endif
 
 #define MAINBOARD_POWER_OFF	0