console: support integrated 7-segment displays for POST codes

Add a configuration option POST_PORT which defaults to 0x80 and
can be redefined by boards which have integrated POST displays
on another I/O port. Change post.c to output POST codes to this
port instead of 0x80 hardcoded.

Change-Id: I8f8e820f8c75641b35e7249bf622b63a3604b9f3
Signed-off-by: Christoph Grenz <christophg+cb@grenz-bonn.de>
Reviewed-on: http://review.coreboot.org/221
Tested-by: build bot (Jenkins)
Reviewed-by: Rudolf Marek <r.marek@assembler.cz>
Reviewed-by: Patrick Georgi <patrick@georgi-clan.de>
diff --git a/src/console/Kconfig b/src/console/Kconfig
index 02244d7d..8382695 100644
--- a/src/console/Kconfig
+++ b/src/console/Kconfig
@@ -333,6 +333,10 @@
 	bool "Don't show any POST codes"
 	default n
 
+config POST_PORT
+	int
+	default 0x80
+
 config CONSOLE_POST
 	bool "Show POST codes on the debug console"
 	depends on !NO_POST
diff --git a/src/console/post.c b/src/console/post.c
index 3872c2d..7fc9d6f 100644
--- a/src/console/post.c
+++ b/src/console/post.c
@@ -32,6 +32,6 @@
 	print_emerg_hex8(value);
 	print_emerg("\n");
 #endif
-	outb(value, 0x80);
+	outb(value, CONFIG_POST_PORT);
 #endif
 }