Provide MRC with a console printing callback function

Let memory initialization code use the coreboot romstage console. This
simplifies the code and makes sure that all output is available in
/sys/firmware/log.

The pei_data structure is modified to allow passing the console output
function pointer. Romstage console_tx_byte() is used for this purpose.

Change-Id: I722cfcb9ff0cf527c12cb6cac09d77ef17b588e0
Signed-off-by: Vadim Bendebury <vbendeb@chromium.org>
Reviewed-on: http://review.coreboot.org/1823
Tested-by: build bot (Jenkins)
Reviewed-by: Martin Roth <martin@se-eng.com>
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>

src/northbridge/intel/sandybridge/raminit.c

@@ -241,6 +241,9 @@ void sdram_initialize(struct pei_data *pei_data)
 		hlt();
 	}
 
+	/* Pass console handler in pei_data */
+	pei_data->tx_byte = console_tx_byte;
+
 	/* Locate and call UEFI System Agent binary. */
 	entry = (unsigned long)cbfs_find_file("mrc.bin", 0xab);
 	if (entry) {