msm: mdss: delay clearing the DSI error interrupt

At present, the DSI error interrupt is cleared before the
respective errors are handled. This might cause re-generation
of the error interrupt which causes the ISR to be scheduled
again. Hence clear the DSI error interrupt after the errors
are handled.

Change-Id: I42b1d0beee8597e60b4103106ebbeffe6caf065e
Signed-off-by: Padmanabhan Komanduru <pkomandu@codeaurora.org>