Add physical port to display viewport

DisplayViewport now also stores the physical port information of the
associated display.
The physical port of the display can be used to match an input device to
the corresponding viewport, therefore ensuring that a specific input
device generates events that go to a particular display.

The associations are provided to InputReaderConfiguration by the JNI
callback.

Change getViewport strategy once more. Now, uniqueId match by itself is
sufficient (viewport type does not need to match if the viewport with
the matching uniqueId is found).
Added a check for assumptions about the number of viewports that can
have the same type. These should be relaxed once (and if) support for
multiple internal viewports is added.

Bug: 116239493
Test: atest -a libinput_tests inputflinger_tests
Change-Id: I1c84f281e8c255f12aea0d15939c70685fe94c41