drm/i915: Use enum pipe consistently

Replace all "int pipe"s with "enum pipe pipe"s to make it clear
what we're dealing with.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190821173033.24123-3-ville.syrjala@linux.intel.com
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 09f29a3..437cd50 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -8858,7 +8858,7 @@ static void ilk_init_clock_gating(struct drm_i915_private *dev_priv)
 
 static void cpt_init_clock_gating(struct drm_i915_private *dev_priv)
 {
-	int pipe;
+	enum pipe pipe;
 	u32 val;
 
 	/*