ecore-drm: Add logical pointer x, y variable in seat for reflecting multiple pointer's movement
Summary: When one pointer moves, we should update the position of other devices.
Test Plan:
(1) Two pointer devices are connected.
(2) Move the cursor to (x, y) position using "device 1".
(3) When you move the cursor using "device 2", the cursor doesn't start from (x, y) position. This causes discontinuous mouse motion.
Reviewers: raster, zmike, gwanglim, stefan_schmidt, devilhorns, ManMower
Reviewed By: devilhorns, ManMower
Subscribers: cedric, Jeon, input.hacker, jpeg
Differential Revision: https://phab.enlightenment.org/D3384