usbdebug: Quirk for board aopen/dxplplusu

This ancient board with Intel e7505 invalidates cache while it does HW
scrubbing for ECC in romstage. This breaks usbdebug console and prevents
system from booting.

If both EARLY_CONSOLE and USBDEBUG are selected, skip ECC scrubbing under
these rare conditions to boot system.

Change-Id: I6cb43bf69af54119f4a582dcaf498dd941d4c62d
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: http://review.coreboot.org/3385
Tested-by: build bot (Jenkins)
Reviewed-by: Marc Jones <marc.jones@se-eng.com>
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
diff --git a/src/mainboard/aopen/dxplplusu/romstage.c b/src/mainboard/aopen/dxplplusu/romstage.c
index 9b96792..98701f9 100644
--- a/src/mainboard/aopen/dxplplusu/romstage.c
+++ b/src/mainboard/aopen/dxplplusu/romstage.c
@@ -70,9 +70,11 @@
 		 * scrub_ecc() are recovered to stack via xmm0-xmm3.
 		 */
 #if CONFIG_HW_SCRUBBER
+#if ! ( CONFIG_USBDEBUG && CONFIG_EARLY_CONSOLE )
 		unsigned long ret_addr = (unsigned long)((unsigned long*)&bist - 1);
 		e7505_mch_scrub_ecc(ret_addr);
 #endif
+#endif
 
 		/* Hook for post ECC scrub settings and debug. */
 		e7505_mch_done(memctrl);