Classify pointing sticks using the input property

BUG=chromium:1114828
TEST=With other CLs in Gestures library and Chromium, check pointing
     stick settings can be changed independently.

Cq-Depend: chromium:2486866
Change-Id: I17c859b8d3da81f52b488c7545a2847b894726ce
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/libevdev/+/2487202
Reviewed-by: Sean O'Brien <seobrien@chromium.org>
Tested-by: Harry Cutts <hcutts@chromium.org>
Commit-Queue: Harry Cutts <hcutts@chromium.org>
diff --git a/src/libevdev.c b/src/libevdev.c
index 797ca49..0602ca7 100644
--- a/src/libevdev.c
+++ b/src/libevdev.c
@@ -524,6 +524,8 @@
     if (TestBit(ABS_MT_POSITION_X, info->abs_bitmask) &&
         TestBit(ABS_MT_POSITION_Y, info->abs_bitmask))
       return EvdevClassMultitouchMouse;
+    else if (TestBit(INPUT_PROP_POINTING_STICK, info->prop_bitmask))
+      return EvdevClassPointingStick;
     else
       return EvdevClassMouse;
   }