x86: Don't duplicate global_ptr in 64-bit EFI app

This variable is already defined by the EFI code. Drop the duplicate
definition when building a 64-bit EFI app.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
diff --git a/arch/x86/cpu/x86_64/cpu.c b/arch/x86/cpu/x86_64/cpu.c
index 8f72c99..a3674e8 100644
--- a/arch/x86/cpu/x86_64/cpu.c
+++ b/arch/x86/cpu/x86_64/cpu.c
@@ -8,20 +8,7 @@
 #include <cpu_func.h>
 #include <debug_uart.h>
 #include <init.h>
-
-/*
- * Global declaration of gd.
- *
- * As we write to it before relocation we have to make sure it is not put into
- * a .bss section which may overlap a .rela section. Initialization forces it
- * into a .data section which cannot overlap any .rela section.
- */
-struct global_data *global_data_ptr = (struct global_data *)~0;
-
-void arch_setup_gd(gd_t *new_gd)
-{
-	global_data_ptr = new_gd;
-}
+#include <asm/global_data.h>
 
 int cpu_has_64bit(void)
 {