Make EARLY_CONSOLE optional

This change brings back the possibility to disable console
output while in romstage, like before commit d2f45c65.

For some platforms (AMD multi-socket) USBDEBUG and/or CBMEM
CONSOLE do not work correctly for romstage due the way
cache-as-ram is set up, but might already work for ramstage.

Change-Id: Id8d830e02a18129af419d3b5860866acf315d531
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: http://review.coreboot.org/3846
Tested-by: build bot (Jenkins)
Reviewed-by: Anton Kochkov <anton.kochkov@gmail.com>
Reviewed-by: Aaron Durbin <adurbin@google.com>
diff --git a/src/console/Kconfig b/src/console/Kconfig
index 013b72f..1d050f7 100644
--- a/src/console/Kconfig
+++ b/src/console/Kconfig
@@ -9,6 +9,7 @@
 
 config EARLY_CONSOLE
 	bool "Enable early (pre-RAM) console output."
+	default y if CACHE_AS_RAM
 	default n
 	help
 	  Use console during early (pre-RAM) boot stages