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/twl4030.c b/drivers/power/twl4030.c
index 42c9001..4cc261a 100644
--- a/drivers/power/twl4030.c
+++ b/drivers/power/twl4030.c
@@ -22,6 +22,7 @@
  *	Syed Mohammed Khasim <khasim at ti.com>
  */
 
+#include <command.h>
 #include <twl4030.h>
 
 /*
@@ -172,7 +173,7 @@
 }
 
 #ifdef CONFIG_CMD_POWEROFF
-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[])
 {
 	twl4030_power_off();