msm: mdss: restore pipe src/dst rect after multiple PU ROI update

During multiple partial update, each pipe is checked against
the two ROIs and the pipe's src and dst rect are cropped and
adjusted with respect to first_roi or second_roi, based on its
position. If the pipe is used with the same configs in the next
kickoff, restore the pipe's actual src/dst before continuing with
the kickoff.

Change-Id: I1db579626d96302e07fef1a755fb39944d3eaca8
Signed-off-by: Veera Sundaram Sankaran <veeras@codeaurora.org>