As all csr firmware related opertion are not using any
any data structures of drm framework level, so better to
use dev_priv instead of dev. it's a new style! :)

Cc: Damien Lespiau <damien.lespiau@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Cc: Sunil Kamath <sunil.kamath@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Signed-off-by: NAnimesh Manna <animesh.manna@intel.com>
Signed-off-by: NImre Deak <imre.deak@intel.com>
Tested-by: Daniel Stone <daniels@collabora.com> # SKL
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1446069547-24760-9-git-send-email-imre.deak@intel.com