With the input_mt_sync_frame() function in place, there is no longer
any need to keep the full touch state in the driver. This patch
removes the slot state and replaces the lookup code with the input-mt
equivalent.
Reviewed-and-tested-by: NBenjamin Tissoires <benjamin.tissoires@enac.fr>
Acked-by: NJiri Kosina <jkosina@suse.cz>
Signed-off-by: NHenrik Rydberg <rydberg@euromail.se>