command: Remove the cmd_tbl_t typedef

We should not use typedefs in U-Boot. They cannot be used as forward
declarations which means that header files must include the full header to
access them.

Drop the typedef and rename the struct to remove the _s suffix which is
now not useful.

This requires quite a few header-file additions.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/usb/gadget/f_rockusb.c b/drivers/usb/gadget/f_rockusb.c
index da3d63c..0c4c83f 100644
--- a/drivers/usb/gadget/f_rockusb.c
+++ b/drivers/usb/gadget/f_rockusb.c
@@ -4,6 +4,7 @@
  *
  * Eddie Cai <eddie.cai.linux@gmail.com>
  */
+#include <command.h>
 #include <config.h>
 #include <common.h>
 #include <env.h>