HID: hid-input: Add suffix also for HID_DG_PEN

This and HID_DG_STYLUS are pretty much the same thing so add suffix for
HID_DG_PEN too. This makes the input device name look better.

While doing this, remove the suffix override from hid-multitouch, as it
is now handled by hid-input. Also, the suffix override done by
hid-multitouch was wrong, as it mapped HID_DG_PEN => "Stylus" and
HID_DG_STYLUS => "Pen".

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Tero Kristo <tero.kristo@linux.intel.com>
[bentiss: amended to keep the same name for hid-multitouch devices]
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Link: https://lore.kernel.org/r/20211210111138.1248187-3-tero.kristo@linux.intel.com