drm/i915: Move intel_display_set_init_power to intel_runtime_pm.c

I've decided to not move intel_display_port_power_domain because
that's just a hack in our design ...

Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

diff --cc drivers/gpu/drm/i915/intel_display.c
Simple merge

diff --cc drivers/gpu/drm/i915/intel_drv.h
Simple merge

diff --cc drivers/gpu/drm/i915/intel_runtime_pm.c
Simple merge