rm unused buttons/axes;

api/lovr/headset/DeviceAxis.lua

@@ -1,10 +1,6 @@
 return {
   description = 'Axes on an input device.',
   values = {
-    {
-      name = 'primary',
-      description = 'The primary analog axis (usually thumbstick or touchpad).'
-    },
     {
       name = 'trigger',
       description = 'A trigger (1D).'
@@ -17,10 +13,6 @@ return {
       name = 'touchpad',
       description = 'A touchpad (2D).'
     },
-    {
-      name = 'pinch',
-      description = 'A tracked pinch gesture between the thumb and index finger (1D, Leap Motion).'
-    },
     {
       name = 'grip',
       description = 'A grip button or grab gesture (1D).'

api/lovr/headset/DeviceButton.lua

@@ -1,10 +1,6 @@
 return {
   description = 'Buttons on an input device.',
   values = {
-    {
-      name = 'primary',
-      description = 'The primary button (usually trigger).'
-    },
     {
       name = 'trigger',
       description = 'The trigger button.'