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/drivers/power/axp209.c b/drivers/power/axp209.c
index 67b4209..60f69ec 100644
--- a/drivers/power/axp209.c
+++ b/drivers/power/axp209.c
@@ -229,7 +229,7 @@
 	return 0;
 }
 
-int do_poweroff(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
+int do_poweroff(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
 {
 	pmic_bus_write(AXP209_SHUTDOWN, AXP209_POWEROFF);