cmd: Remove <common.h> and add needed includes

Remove <common.h> from all "cmd/" files and when needed add
missing include files directly.

Signed-off-by: Tom Rini <trini@konsulko.com>

cmd/exit.c

@@ -4,8 +4,8 @@
  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
  */
 
-#include <common.h>
 #include <command.h>
+#include <vsprintf.h>
 
 static int do_exit(struct cmd_tbl *cmdtp, int flag, int argc,
 		   char *const argv[])