add hid stylus pen device.

this works with android, for bypassing that absmouse does not support android.
note that, to hide cursor on android for every touch signal, find cursor option in android settings menu.

references:
1. https://stackoverflow.com/questions/28536602/hid-digitizer-descriptor-doesnt-perform-well-with-landscape-orientation
2. https://github.com/jonathanedgecombe/absmouse/blob/master/src/AbsMouse.cpp

examples/device/hid_composite/src/usb_descriptors.c

@@ -79,6 +79,7 @@ uint8_t const desc_hid_report[] =
 {
   TUD_HID_REPORT_DESC_KEYBOARD( HID_REPORT_ID(REPORT_ID_KEYBOARD         )),
   TUD_HID_REPORT_DESC_MOUSE   ( HID_REPORT_ID(REPORT_ID_MOUSE            )),
+  TUD_HID_REPORT_DESC_STYLUS_PEN( HID_REPORT_ID(REPORT_ID_STYLUS_PEN     )),
   TUD_HID_REPORT_DESC_CONSUMER( HID_REPORT_ID(REPORT_ID_CONSUMER_CONTROL )),
   TUD_HID_REPORT_DESC_GAMEPAD ( HID_REPORT_ID(REPORT_ID_GAMEPAD          ))
 };