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>

cmd/setexpr.c

@@ -290,7 +290,8 @@ static int regex_sub(const char *name,
 }
 #endif
 
-static int do_setexpr(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
+static int do_setexpr(struct cmd_tbl *cmdtp, int flag, int argc,
+		      char *const argv[])
 {
 	ulong a, b;
 	ulong value;