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/time.c b/cmd/time.c
index 51cde97..db8c189 100644
--- a/cmd/time.c
+++ b/cmd/time.c
@@ -24,7 +24,8 @@
 	printf(" %lu.%03lu seconds\n", seconds, milliseconds);
 }
 
-static int do_time(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
+static int do_time(struct cmd_tbl *cmdtp, int flag, int argc,
+		   char *const argv[])
 {
 	ulong cycles = 0;
 	int retval = 0;