rockchip: Set config_store before qbuf

BUG=chrome-os-partner:33728
TEST='
build plugin lib
put it under /usr/local/lib/libv4l/plugins/
update kernel to https://chromium-review.googlesource.com/#/c/232587/5
run "./video_encode_accelerator_unittest 
--test_stream_data=./bear_320x192_40frames.yuv:320:192:11:/tmp/out.vp8:200000"
check /tmp/out.vp8
'

Change-Id: I5343e6832d8b96bc773cfe74475c98a4dc993cfa
Reviewed-on: https://chromium-review.googlesource.com/235602


Reviewed-by: Pawel Osciak <posciak@chromium.org>
Commit-Queue: Jeffy Chen <jeffy.chen@rock-chips.com>
Tested-by: Jeffy Chen <jeffy.chen@rock-chips.com>