synaptics: add test for SoftButtonAreas option
synaptics: add test for SoftButtonAreas option

This option is assigned by the xorg.conf.d, so this test merely checks for
zeros. A warning flag for potential changed behaviours in the future.

Signed-off-by: Peter Hutterer <b9c50af7afa7642f6f854434cda9ffe54ece8b85@who-t.net>

freedesktop-unofficial-mirror/xorg__test__xorg-integration-tests,freedesktop-unofficial-mirror/xorg__test__xorg-integration-tests,freedesktop-unofficial-mirror/xorg__test__xorg-integration-tests