x86: Rename efi-x86 target to efi-x86_app

To avoid confusion, let's rename the efi-x86 target to efi-x86_app.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/board/efi/efi-x86_app/Makefile b/board/efi/efi-x86_app/Makefile
new file mode 100644
index 0000000..cb48d1c
--- /dev/null
+++ b/board/efi/efi-x86_app/Makefile
@@ -0,0 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0+
+#
+# Copyright (c) 2015 Google, Inc
+
+obj-y	+= app.o