tsc2007: Set input property bit to indicate a direct input device

Prop bit is checked in userspace and must be set in
driver in order to be recognized correctly, since it defaults
to mouse pointer.

Change-Id: I5eadfe45baac93b9e315381dcacc5a02c27bc0c9
Signed-off-by: Amy Maloche <amaloche@codeaurora.org>