U-Boot 移植：全局变量结构体定义

--- a/arch/arm/include/asm/global_data.h
+++ b/arch/arm/include/asm/global_data.h
@@ -25,6 +25,16 @@ struct arch_global_data {
        uint mp_alloc_top;
 #endif /* CONFIG_U_QE */

+#ifdef CONFIG_ASM9260
+       /* "static data" needed by at91's clock.c */
+       unsigned long   cpu_clk_rate_hz;
+       unsigned long   main_clk_rate_hz;
+       unsigned long   mck_rate_hz;
+       unsigned long   plla_rate_hz;
+       unsigned long   pllb_rate_hz;
+       unsigned long   at91_pllb_usb_init;
+#endif
+