x86: fsp: Wrap setup_internal_uart() call with CONFIG_INTERNAL_UART

For any FSP-enabled boards that want to enable debug UART support,
setup_internal_uart() will be called, but this API is only available
on BayTrail platform. Change to wrap it with CONFIG_INTERNAL_UART.
Signed-off-by: NBin Meng <bmeng.cn@gmail.com>
Reviewed-by: NStefan Roese <sr@denx.de>
Reviewed-by: NSimon Glass <sjg@chromium.org>

arch/x86/lib/fsp/fsp_support.c

@@ -110,7 +110,7 @@ void fsp_init(u32 stack_top, u32 boot_mode, void *nvs_buf)
 	struct upd_region *fsp_upd;
 #endif
 
-#ifdef CONFIG_DEBUG_UART
+#ifdef CONFIG_INTERNAL_UART
 	setup_internal_uart(1);
 #endif