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>

diff --cc drivers/hid/wacom_sys.c
Simple merge

diff --cc drivers/hid/wacom_wac.c
Simple merge

diff --cc drivers/hid/wacom_wac.h
Simple merge

diff --cc include/uapi/linux/input.h
Simple merge