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/cmd/usb.c b/cmd/usb.c
index 858be72..b9ec29a 100644
--- a/cmd/usb.c
+++ b/cmd/usb.c
@@ -556,7 +556,8 @@
  * usb boot command intepreter. Derived from diskboot
  */
 #ifdef CONFIG_USB_STORAGE
-static int do_usbboot(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
+static int do_usbboot(struct cmd_tbl *cmdtp, int flag, int argc,
+		      char *const argv[])
 {
 	return common_diskboot(cmdtp, "usb", argc, argv);
 }
@@ -625,7 +626,7 @@
 /******************************************************************************
  * usb command intepreter
  */
-static int do_usb(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
+static int do_usb(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
 {
 	struct usb_device *udev = NULL;
 	int i;