drm/komeda: Correct the sequence of hw_done() and flip_done()

Komeda HW has no special, program the update to HW is done first,
then flip happens. So correct the sequence to hw_done() first then
flip_done().

Reported-by: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: James Qian Wang <james.qian.wang@arm.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Liviu Dudau <liviu.dudau@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201119013948.2866343-1-james.qian.wang@arm.com