msm: mdss: program correct value of height for tear check block

The current calculation of sync_cfg_height for tear check block
follows old approach whereas the other tear check parameters are
configured in accordance with free running mode approach. This can
cause double read pointer issues with certain configurations.
Update the calculation of sync_cfg_height to follow the free
running mode approach for MDP3 based targets.

Change-Id: I9922e2b81a6b7241f1808e772b39cd6de5abd27e
Signed-off-by: Padmanabhan Komanduru <pkomandu@codeaurora.org>
Signed-off-by: Krishna Manikandan <mkrishn@codeaurora.org>