drm/msm/sde: insert extra inline rotator flush

Set the rotator flush mask for the first frame after an
inline rotation operation to allow the hardware to
transition out of inline rotation mode correctly.

CRs-Fixed: 2056550
Change-Id: I993565a1850031a29b7079fe25c72d6f1ba48dcf
Signed-off-by: Clarence Ip <cip@codeaurora.org>