x86: Declare global_data pointer when it is used

Several files use the global_data pointer without declaring it. This works
because the declaration is currently a NOP. But still it is better to
fix this so that x86 lines up with other archs.

Signed-off-by: Simon Glass <sjg@chromium.org>

arch/x86/cpu/interrupts.c

@@ -37,6 +37,8 @@
 #include <asm/msr.h>
 #include <asm/u-boot-x86.h>
 
+DECLARE_GLOBAL_DATA_PTR;
+
 #define DECLARE_INTERRUPT(x) \
 	".globl irq_"#x"\n" \
 	".hidden irq_"#x"\n" \

arch/x86/lib/cmd_boot.c

@@ -36,6 +36,8 @@
 #include <malloc.h>
 #include <asm/u-boot-x86.h>
 
+DECLARE_GLOBAL_DATA_PTR;
+
 unsigned long do_go_exec(ulong (*entry)(int, char * const []),
 			 int argc, char * const argv[])
 {

arch/x86/lib/physmem.c

@@ -12,6 +12,8 @@
 #include <physmem.h>
 #include <linux/compiler.h>
 
+DECLARE_GLOBAL_DATA_PTR;
+
 /* Large pages are 2MB. */
 #define LARGE_PAGE_SIZE ((1 << 20) * 2)
 

arch/x86/lib/relocate.c

@@ -39,6 +39,8 @@
 #include <asm/sections.h>
 #include <elf.h>
 
+DECLARE_GLOBAL_DATA_PTR;
+
 int copy_uboot_to_ram(void)
 {
 	size_t len = (size_t)&__data_end - (size_t)&__text_start;

arch/x86/lib/timer.c

@@ -30,6 +30,8 @@
 #include <asm/i8254.h>
 #include <asm/ibmpc.h>
 
+DECLARE_GLOBAL_DATA_PTR;
+
 struct timer_isr_function {
 	struct timer_isr_function *next;
 	timer_fnc_t *isr_func;