Revert "SpinBox: hide VKB when appropriate"

This reverts commit e64180b65cd9dfc2ff008dc5725ff0e58a833cd7.
TextInput does commit & hide no need to do it here

Change-Id: I29c9e9421afd957457c648dc07270ee5dd7ca8e5
Reviewed-by: J-P Nurmi <jpnurmi@theqtcompany.com>