msm: camera: isp: adjust irq processing order

When buf done and sof comes at around the same time,
always process buf done first then sof to garantee the
frame id is not increased wrongly.

Change-Id: Id3a34f40a2863b8c06eb87389147803bfd2c51bf
Signed-off-by: Peter Liu <pingchie@codeaurora.org>