global_data.h: make <asm-generic/global_data.h> self-contained

The compiler never knows what 'bd_t' is without including <asm/u-boot.h>.

By changing it to (struct bd_info), the compiler learns it is struct.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
diff --git a/include/asm-generic/global_data.h b/include/asm-generic/global_data.h
index 5d02732..d9e220c 100644
--- a/include/asm-generic/global_data.h
+++ b/include/asm-generic/global_data.h
@@ -25,7 +25,7 @@
 #include <linux/list.h>
 
 typedef struct global_data {
-	bd_t *bd;
+	struct bd_info *bd;
 	unsigned long flags;
 	unsigned int baudrate;
 	unsigned long cpu_clk;		/* CPU clock in Hz!		*/