platform/x86: intel-vbtn: Remove unused KEYMAP_LEN define

Now that we have 2 separate input_dev-s for the buttons and the switches,
this is no longer used, remove it.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20210325123255.73103-1-hdegoede@redhat.com

drivers/platform/x86/intel-vbtn.c

@@ -63,9 +63,6 @@ static const struct key_entry intel_vbtn_switchmap[] = {
 	{ KE_END }
 };
 
-#define KEYMAP_LEN \
-	(ARRAY_SIZE(intel_vbtn_keymap) + ARRAY_SIZE(intel_vbtn_switchmap) + 1)
-
 struct intel_vbtn_priv {
 	struct input_dev *buttons_dev;
 	struct input_dev *switches_dev;