Revert "Add helm keymap"

This reverts commit 7106541f1f.

emacs.el

@@ -566,10 +566,6 @@ found, otherwise returns nil."
   (defvar amx-map)
   (define-key amx-map (kbd "C-h") (kbd "DEL")))
 
-(when (autoload-eval-lazily 'helm)
-  (defvar helm-map)
-  (define-key helm-map (kbd "C-h") (kbd "DEL")))
-
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;; letters, font-lock mode and fonts