HID: lg: fix ReportDescriptor for Logitech Formula Vibration

By default the Logitech Formula Vibration presents a combined accel/brake
axis ('Y'). This patch modifies the HID descriptor to present seperate
accel/brake axes ('Y' and 'Z').

Signed-off-by: Simon Wood <simon@mungewell.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>