x86: Permit bootstage and timer data to be used prior to relocation

It is useful to be able to access the timer before U-Boot has relocated
so that we can fully support bootstage.

Add new global_data members to support this.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/x86/include/asm/global_data.h b/arch/x86/include/asm/global_data.h
index 8a96fc9..2f84abd 100644
--- a/arch/x86/include/asm/global_data.h
+++ b/arch/x86/include/asm/global_data.h
@@ -29,6 +29,9 @@
 /* Architecture-specific global data */
 struct arch_global_data {
 	struct global_data *gd_addr;		/* Location of Global Data */
+	uint64_t tsc_base;		/* Initial value returned by rdtsc() */
+	uint32_t tsc_base_kclocks;	/* Initial tsc as a kclocks value */
+	uint32_t tsc_prev;		/* For show_boot_progress() */
 };
 
 #endif