HID: add driver for the Logitech Flight System G940

Implements a new USB-HID for Force Feedback based on the normal
Logitech Force Feedback code and FF-Memless.

Currently only supports the FF_CONSTANT effect although the joystick
appears to support additional non-standard ones.

Signed-off-by: Gary Stein <LordCnidarian@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

diff --cc drivers/hid/Kconfig
Simple merge

diff --cc drivers/hid/Makefile
Simple merge

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

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

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

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

diff --cc drivers/hid/hid-lg3ff.c
Simple merge

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