HID: uclogic: Always shift touch reports to zero

Always decrement touch report values to have the range start with zero,
regardless if flipped or not. This fixes the future non-flipped touch
strip reports.

Signed-off-by: Nikolai Kondrashov <spbnick@gmail.com>
Signed-off-by: José Expósito <jose.exposito89@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>