Create x_min, y_min and max_fingers variables for set correct XY minimum value
and the number of max finger on each devices.

[jkosina@suse.cz: update shortlog]
Signed-off-by: NMasaki Ota <masaki.ota@jp.alps.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>