msm: vidc: fix the interrupt miss issue from video hardware

enable_irq() called before processing responses in work handler
which would lead to miss interrupt from video hardware sometimes.
An interrupt from video h/w will queue the work to work handler
but if work is already running the new work is not posted.
work handler has two parts, one, read all the messages from video h/w,
two, process the messages. queue work while processing messages
will miss reading the new messages from video h/w because
the queue work (as a result of interrupt from video h/w) will not
actually queue the work as work handler already running. Fix the
issue by enabling irq after processing all the responses to
makesure interrupt coming from video h/w after work handler
completed processing the messages.

CRs-Fixed: 1086284
Change-Id: Id158e5c6d89fc8b761d8cfe92afbf3592877c556
Signed-off-by: Karthikeyan Periasamy <kperiasa@codeaurora.org>