HID: wacom: add support for Cintiq 27QHD and 27QHD touch

These devices have accelerometers. To report accelerometer coordinates, a new
property, INPUT_PROP_ACCELEROMETER, is added.

Signed-off-by: Ping Cheng <pingc@wacom.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>