x86: Rename coreboot-serial to x86-serial

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Simon Glass <sjg@chromium.org>
diff --git a/include/configs/crownbay.h b/include/configs/crownbay.h
index b9db6b7..eadb339 100644
--- a/include/configs/crownbay.h
+++ b/include/configs/crownbay.h
@@ -20,7 +20,7 @@
 #define CONFIG_X86_RESET_VECTOR
 #define CONFIG_NR_DRAM_BANKS		1
 
-#define CONFIG_COREBOOT_SERIAL
+#define CONFIG_X86_SERIAL
 #define CONFIG_SMSC_LPC47M
 
 #define CONFIG_PCI_MEM_BUS		0x40000000