x86: Add support for U-Boot as an EFI application

Add the required x86 glue code. This includes the initial start-up,
relocation and jumping to efi_main(). We also need to avoid fiddling with
interrupts.

Signed-off-by: Ben Stoltz <stoltz@google.com>
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/arch/x86/cpu/interrupts.c b/arch/x86/cpu/interrupts.c
index 3a9c2d4..a112938 100644
--- a/arch/x86/cpu/interrupts.c
+++ b/arch/x86/cpu/interrupts.c
@@ -242,6 +242,11 @@
 
 int interrupt_init(void)
 {
+	/*
+	 * When running as an EFI application we are not in control of
+	 * interrupts and should leave them alone.
+	 */
+#ifndef CONFIG_EFI_APP
 	/* Just in case... */
 	disable_interrupts();
 
@@ -255,6 +260,7 @@
 
 	/* It is now safe to enable interrupts */
 	enable_interrupts();
+#endif
 
 	return 0;
 }