treewide: convert bd_t to struct bd_info by coccinelle

The Linux coding style guide (Documentation/process/coding-style.rst)
clearly says:

  It's a **mistake** to use typedef for structures and pointers.

Besides, using typedef for structures is annoying when you try to make
headers self-contained.

Let's say you have the following function declaration in a header:

  void foo(bd_t *bd);

This is not self-contained since bd_t is not defined.

To tell the compiler what 'bd_t' is, you need to include <asm/u-boot.h>

  #include <asm/u-boot.h>
  void foo(bd_t *bd);

Then, the include direcective pulls in more bloat needlessly.

If you use 'struct bd_info' instead, it is enough to put a forward
declaration as follows:

  struct bd_info;
  void foo(struct bd_info *bd);

Right, typedef'ing bd_t is a mistake.

I used coccinelle to generate this commit.

The semantic patch that makes this change is as follows:

  <smpl>
  @@
  typedef bd_t;
  @@
  -bd_t
  +struct bd_info
  </smpl>

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
diff --git a/include/image.h b/include/image.h
index 9ababf2..9a5a87d 100644
--- a/include/image.h
+++ b/include/image.h
@@ -412,7 +412,7 @@
 	ulong		initrd_end;
 	ulong		cmdline_start;
 	ulong		cmdline_end;
-	bd_t		*kbd;
+	struct bd_info		*kbd;
 #endif
 
 	int		verify;		/* env_get("verify")[0] != 'n' */
@@ -755,7 +755,7 @@
 		  ulong *initrd_start, ulong *initrd_end);
 int boot_get_cmdline(struct lmb *lmb, ulong *cmd_start, ulong *cmd_end);
 #ifdef CONFIG_SYS_BOOT_GET_KBD
-int boot_get_kbd(struct lmb *lmb, bd_t **kbd);
+int boot_get_kbd(struct lmb *lmb, struct bd_info **kbd);
 #endif /* CONFIG_SYS_BOOT_GET_KBD */
 #endif /* !USE_HOSTCC */