HID: 3m: Adjust major / minor axes to scale

By visual inspection, the reported touch_major and touch_minor axes
are a factor of two too large. Presumably the device actually reports
the width_major and width_minor, which are generally about a factor of
two larger than the touches themselves.

Signed-off-by: Henrik Rydberg <rydberg@euromail.se>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>