drm/i915: Constify power well descriptors

It makes sense to keep unchanging data const. Extract such fields from
the i915_power_well struct into a new i915_power_well_desc struct that
we initialize during compile time. For the rest of the dynamic
fields allocate an array of i915_power_well objects in i915 dev_priv,
and link to each of these objects their corresponding
i915_power_well_desc object.

v2:
- Fix checkpatch warnings about missing param name in fn declaration and
  lines over 80 chars. (Paulo)
- Move check for unique IDs to __set_power_wells().

Cc: Ville Syrjala <ville.syrjala@linux.intel.com>
Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
[Fixed checkpatch warn in __set_power_wells()]
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180806095843.13294-5-imre.deak@intel.com
diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 6396318..9dce551 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -924,7 +924,9 @@ static int i915_driver_init_early(struct drm_i915_private *dev_priv,
 	intel_uc_init_early(dev_priv);
 	intel_pm_setup(dev_priv);
 	intel_init_dpio(dev_priv);
-	intel_power_domains_init(dev_priv);
+	ret = intel_power_domains_init(dev_priv);
+	if (ret < 0)
+		goto err_uc;
 	intel_irq_init(dev_priv);
 	intel_hangcheck_init(dev_priv);
 	intel_init_display_hooks(dev_priv);
@@ -936,6 +938,9 @@ static int i915_driver_init_early(struct drm_i915_private *dev_priv,
 
 	return 0;
 
+err_uc:
+	intel_uc_cleanup_early(dev_priv);
+	i915_gem_cleanup_early(dev_priv);
 err_workqueues:
 	i915_workqueues_cleanup(dev_priv);
 err_engines:
@@ -950,6 +955,7 @@ static int i915_driver_init_early(struct drm_i915_private *dev_priv,
 static void i915_driver_cleanup_early(struct drm_i915_private *dev_priv)
 {
 	intel_irq_fini(dev_priv);
+	intel_power_domains_cleanup(dev_priv);
 	intel_uc_cleanup_early(dev_priv);
 	i915_gem_cleanup_early(dev_priv);
 	i915_workqueues_cleanup(dev_priv);