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>

common/spl/spl.c

@@ -54,7 +54,7 @@ binman_sym_declare(ulong, spl, size);
 #endif
 
 /* Define board data structure */
-static bd_t bdata __attribute__ ((section(".data")));
+static struct bd_info bdata __attribute__ ((section(".data")));
 
 /*
  * Board-specific Platform code can reimplement show_boot_progress () if needed