Revert "wayland: Emulate tablet events only if there is pointer"

This reverts commit ee54fa7898.

Unfortunately, this is not a totally correct fix. If there's no pointer,
we need to announce the wl_pointer capability anyway so clients that do
not support tablet input devices can still receive emulated pointer
events.

src/input.cpp

@@ -1776,7 +1776,7 @@ public:
 
     bool emulateTabletEvent(TabletEvent *event)
     {
-        if (!workspace() || !waylandServer()->seat()->hasPointer()) {
+        if (!workspace()) {
             return false;
         }