Input: wacom - rearrange type enum

So we can simplify a few type related if statements

Signed-off-by: Ping Cheng <pingc@wacom.com>
Acked-by: Chris Bagwell <chris@cnpbagwell.com>
Reviewed-by: Jason Gerecke <killertofu@gmail.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>