msm: mdss: Update notify on assertive display calculation

When assertive display finishes a calculation it will cause an update to
the values on the screen independent of display commits. This maintains the
logic of the update notify ioctl.

Change-Id: I6a633931db3220b33def17aa1ec1c97207c2c2fd
Signed-off-by: Carl Vanderlip <carlv@codeaurora.org>