disp: msm: sde: update frame done logic during pp_done miss scenario

In few cases, pp-done interrupt is missed due to irq
latency with POSTED start and frame done count is not
updated accordingly. This change updates frame done
logic to handle such scenarios.

Issue Scenario:                 Earlier         Now
                              enc-0 enc-1   enc-0 enc-1
--> pp0 processed               1    0        1    0
--> pp1 missed                  1    0        1    0
--> pp0 processed and error is  1    0        2    0
    returned in first case.
--> pp1 processed               1    1        2    1
--> After signalling frame done 0    0        1    0
    for both encoders
--> pp done irq miss handler    0    1        1    1
--> After signalling frame done 0    1        0    0
    only for second encoder.

Change-Id: If29457011ec54a3b0254ec351d4a48ceb76614e6
Signed-off-by: Yashwanth <yvulapu@codeaurora.org>