drm/i915/gen9: csr_init after runtime pm enable

Skl is fully dependent on dmc for going to low power state (dc5/dc6).
This requires a trigger from rpm. To ensure the dmc firmware
is available for runtime pm support rpm-reference-count is used
by not releasing the rpm reference if firmware loading is
not completed.

So moved the intel_csr_ucode_init call after runtime pm enable.

Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Damien Lespiau <damien.lespiau@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Cc: Sunil Kamath <sunil.kamath@intel.com>
Signed-off-by: Animesh Manna <animesh.manna@intel.com>
[imre: moved the call right after power domain init to avoid race with
 the console modesetting]
Signed-off-by: Imre Deak <imre.deak@intel.com>
Tested-by: Daniel Stone <daniels@collabora.com> # SKL
Reviewed-by: A.Sunil Kamath <sunil.kamath@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1446069547-24760-2-git-send-email-imre.deak@intel.com