drm/i915: Extract a intel_power_well_enable() function

We need a bit book keeping around power wells' ops->enable(), namely a
nice debug message and updating hw_enabled. Let's introduce a
intel_power_well_enable() function to make sure all the callers do the
same things.

v2 (from Paulo):
  - s/i915_power_well_enable/intel_power_well_enable/ since everything
    else on this file uses intel_ instead of i915_.
  - Fix typo in commit message.

Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_runtime_pm.c

@@ -68,6 +68,14 @@
 bool intel_display_power_well_is_enabled(struct drm_i915_private *dev_priv,
 				    int power_well_id);
 
+static void intel_power_well_enable(struct drm_i915_private *dev_priv,
+				    struct i915_power_well *power_well)
+{
+	DRM_DEBUG_KMS("enabling %s\n", power_well->name);
+	power_well->ops->enable(dev_priv, power_well);
+	power_well->hw_enabled = true;
+}
+
 /*
  * We should only use the power well if we explicitly asked the hardware to
  * enable it, so check if it's enabled and also check if we've requested it to
@@ -1104,11 +1112,8 @@ void intel_display_power_get(struct drm_i915_private *dev_priv,
 	mutex_lock(&power_domains->lock);
 
 	for_each_power_well(i, power_well, BIT(domain), power_domains) {
-		if (!power_well->count++) {
-			DRM_DEBUG_KMS("enabling %s\n", power_well->name);
-			power_well->ops->enable(dev_priv, power_well);
-			power_well->hw_enabled = true;
-		}
+		if (!power_well->count++)
+			intel_power_well_enable(dev_priv, power_well);
 	}
 
 	power_domains->domain_use_count[domain]++;