Remove GTP_ICS_SLOT_REPORT configuration

We do have slot reporting, even if we're not Ice-Cream Sandwich
Remove ability to send custom configuration

This removes the 2 unused configuration options
GTP_CUSTOM_CFG and GTP_DRIVER_SEND_CFG.
Remove GTP_HAVE_TOUCH_KEY configuration option

A follow-up to 89b95c143b76d1c3828442cead954993987c6aca
Remove unused GUP_USE_HEADER_FILE