Swap M-x and C-x C-m keybindings between smex and helm-command

I mostly use C-x C-m instead of M-x as I for some reason find it less
annoying to type. I really like helm-command's helm-M-x function, but I
find slightly too slow and slightly too intrusive than smex.

Hence I'm switching back my main keybinding to smex, but still leaving
helm-M-x bound to the M-x keybinding I use very rarely, just so I can
still access it when I need to.

modules/editor/siren-helm-command.el

@@ -12,8 +12,7 @@
   :ensure helm
   :defer t
   :bind
-  ("C-x C-m" . helm-M-x)
-  ("C-c C-m" . helm-M-x)
+  ("M-x" . helm-M-x)
 
   :config
   (setq helm-M-x-always-save-history t