drm/i915: Bikeshed rpm functions name a bit.

- fini goes with init, so call it intel_power_domains_fini. While
  at it shovel some of the fini code that leaked out of it back in.

- give power_enabled functions the verb _is_ to make the meaning clearer.
  Also use a __ prefix instead of _unlocked to really discourage users.

- rename runtime_pm_init/fini to enable/disable since that's what they do.

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

drivers/gpu/drm/i915/intel_dp.c

@@ -1853,7 +1853,7 @@ static bool intel_dp_get_hw_state(struct intel_encoder *encoder,
 	u32 tmp;
 
 	power_domain = intel_display_port_power_domain(encoder);
-	if (!intel_display_power_enabled(dev_priv, power_domain))
+	if (!intel_display_power_is_enabled(dev_priv, power_domain))
 		return false;
 
 	tmp = I915_READ(intel_dp->output_reg);