mouse: Hide entire "Touchpad" row when touchpad cannot be disabled
The touchpad row has a switch suffix that allows enabling/disabling touchpad.
To prevent users from being left with no pointer device, we were hiding the suffix switch of the touchpad row, making the row look weird with a label and no action.
Let's hide the entire row instead, as suggested by designers in comment #1649 (comment 1643002)
Fixes #1649 (closed)