common/board_f: Initialized global data for generic board

Some platforms (tested on mpc85xx, mpc86xx) use global data before calling
function baord_inti_f(). The data should not be cleared later. Any arch
which uses global data in generic board board_init_f() should define
CONFIG_SYS_GENERIC_GLOBAL_DATA.

Signed-off-by: York Sun <yorksun@freescale.com>
CC: Scott Wood <scottwood@freescale.com>
CC: Simon Glass <sjg@chromium.org>
CC: Albert ARIBAUD <albert.u.boot@aribaud.net>
Acked-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/sandbox/include/asm/config.h b/arch/sandbox/include/asm/config.h
index ec7729e..6c1bff9 100644
--- a/arch/sandbox/include/asm/config.h
+++ b/arch/sandbox/include/asm/config.h
@@ -7,6 +7,7 @@
 #ifndef _ASM_CONFIG_H_
 #define _ASM_CONFIG_H_
 
+#define CONFIG_SYS_GENERIC_GLOBAL_DATA
 #define CONFIG_SANDBOX_ARCH
 
 /* Used by drivers/spi/sandbox_spi.c and arch/sandbox/include/asm/state.h */