src/console: Add x86 romstage spinlock option and printk spinlock support

This paves the way for AP printk spinlock on AMD platforms

Change-Id: Ice42a0d3177736bf6e1bc601092e413601866f20
Signed-off-by: Timothy Pearson <tpearson@raptorengineeringinc.com>
Reviewed-on: https://review.coreboot.org/11958
Tested-by: Raptor Engineering Automated Test Stand <noreply@raptorengineeringinc.com>
Tested-by: build bot (Jenkins)
Reviewed-by: Martin Roth <martinroth@google.com>

src/cpu/amd/car/post_cache_as_ram.c

@@ -76,6 +76,10 @@ static void prepare_ramstage_region(void *resume_backup_memory)
 		memset_((void*)0, 0, CONFIG_RAMTOP - backup_top);
 	}
 
+#if IS_ENABLED(CONFIG_HAVE_ROMSTAGE_CONSOLE_SPINLOCK)
+	initialize_romstage_console_lock();
+#endif
+
 	print_car_debug(" Done\n");
 }