Extend CMOS POST code logging to store extra data

This can be used to indicate sub-state within a POST
code range which can assist in debugging BIOS hangs.

For example this can be used to indicate which device
is about to be initialized so if the system hangs
while talking to that device it can be identified.

Change-Id: I2f8155155f09fe9e242ebb7204f0b5cba3a1fa1e
Signed-off-by: Duncan Laurie <dlaurie@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/58104
Reviewed-on: http://review.coreboot.org/4229
Tested-by: build bot (Jenkins)
Reviewed-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>

src/include/console/console.h

@@ -72,6 +72,11 @@ void console_init(void);
 void console_tx_byte(unsigned char byte);
 void console_tx_flush(void);
 void post_code(u8 value);
+#if CONFIG_CMOS_POST_EXTRA
+void post_log_extra(u32 value);
+#else
+#define post_log_extra(x) do {} while (0)
+#endif
 /* this function is weak and can be overridden by a mainboard function. */
 void mainboard_post(u8 value);
 void __attribute__ ((noreturn)) die(const char *msg);