x86: Add some missing global_data declarations in files that use gd

Some files use global_data but don't declare it. Fix this.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>

arch/x86/cpu/mp_init.c

@@ -24,6 +24,8 @@
 #include <dm/uclass-internal.h>
 #include <linux/linkage.h>
 
+DECLARE_GLOBAL_DATA_PTR;
+
 /* Total CPUs include BSP */
 static int num_cpus;
 

arch/x86/lib/bootm.c

@@ -22,6 +22,8 @@
 #include <asm/arch/timestamp.h>
 #endif
 
+DECLARE_GLOBAL_DATA_PTR;
+
 #define COMMAND_LINE_OFFSET 0x9000
 
 /*

arch/x86/lib/fsp/fsp_common.c

@@ -11,6 +11,8 @@
 #include <asm/processor.h>
 #include <asm/fsp/fsp_support.h>
 
+DECLARE_GLOBAL_DATA_PTR;
+
 int print_cpuinfo(void)
 {
 	post_code(POST_CPU_INFO);

arch/x86/lib/lpc-uclass.c

@@ -9,6 +9,8 @@
 #include <dm.h>
 #include <dm/root.h>
 
+DECLARE_GLOBAL_DATA_PTR;
+
 static int lpc_uclass_post_bind(struct udevice *bus)
 {
 	/*

arch/x86/lib/pch-uclass.c

@@ -9,6 +9,8 @@
 #include <dm.h>
 #include <dm/root.h>
 
+DECLARE_GLOBAL_DATA_PTR;
+
 static int pch_uclass_post_bind(struct udevice *bus)
 {
 	/*

drivers/gpio/intel_ich6_gpio.c

@@ -35,6 +35,8 @@
 #include <asm/io.h>
 #include <asm/pci.h>
 
+DECLARE_GLOBAL_DATA_PTR;
+
 #define GPIO_PER_BANK	32
 
 struct ich6_bank_priv {