HID: bpf: add heuristics to the Huion Inspiroy 2S eraser button

HID: bpf: add heuristics to the Huion Inspiroy 2S eraser button

When pressing the phsyical eraser button (remapped by us to the
Secondary Barrel Switch) while the tip is down, the device
gives us several false reports with a Tip Switch 0:

         press|           |release
SBS: [0 0 ... 1 1 1 ... 1 0 0 0 0 0 0 ...]
 TS: [1 1 ... 1 0 1 ... 1 1 0 0 0 1 1 ...]

In both press/release the number of Tip Switch 0 reports can be up to 4
and *sometimes* the Tip Switch is released in the same report
as the button press/release event.

Paper over this by forcing the tip down for a few reports if it was down
before the button toggled.

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Link: https://gitlab.freedesktop.org/libevdev/udev-hid-bpf/-/merge_requests/195
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
Signed-off-by: Jiri Kosina <jkosina@suse.com>