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>

lib/efi_loader/efi_variable.c

@@ -7,6 +7,7 @@
 
 #include <common.h>
 #include <efi_loader.h>
+#include <env.h>
 #include <env_internal.h>
 #include <hexdump.h>
 #include <malloc.h>