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/unlz4.c b/cmd/unlz4.c
index 5320b37..4ae7f34 100644
--- a/cmd/unlz4.c
+++ b/cmd/unlz4.c
@@ -9,7 +9,8 @@
 #include <env.h>
 #include <lz4.h>
 
-static int do_unlz4(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
+static int do_unlz4(struct cmd_tbl *cmdtp, int flag, int argc,
+		    char *const argv[])
 {
 	unsigned long src, dst;
 	size_t src_len = ~0UL, dst_len = ~0UL;