Add initial pressure calibration for Lulu

This will probably have to be re-done after the FW is finalized, but
we need to get something in that works with the current FW for FSI.

BUG=chrome-os-partner:41922
TEST=manuall emerged onto a Lulu and the touchpad seems to work with it.
Changing the values to large ones made it not work, too, so we know that
it was actually applying the calibration.

Change-Id: If0a39c756100d9bd31f3ddb8acb1e0c104533f42
Signed-off-by: Charlie Mooney <charliemooney@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/282270
Reviewed-by: Dennis Kempin <denniskempin@chromium.org>
(cherry picked from commit e5e2b9d77d6ba9e8f13bef65058b6739ec2e67a2)
Reviewed-on: https://chromium-review.googlesource.com/283002