drm/i915: Consistently use enum pipe for PCH transcoders

The current code uses in some instances enum transcoder for PCH
transcoders and enum pipe in others. This is error prone and clang
raises warnings like this:

drivers/gpu/drm/i915/intel_dp.c:3546:51: warning: implicit conversion
  from enumeration type 'enum pipe' to different enumeration type
  'enum transcoder' [-Wenum-conversion]
    intel_set_pch_fifo_underrun_reporting(dev_priv, PIPE_A, false);

Consistently use the type enum pipe for PCH transcoders.

Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20170717181403.57324-1-mka@chromium.org
diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index 1d33cea..0b6f310 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -2086,10 +2086,10 @@ static void ibx_irq_handler(struct drm_i915_private *dev_priv, u32 pch_iir)
 		DRM_DEBUG_DRIVER("PCH transcoder CRC error interrupt\n");
 
 	if (pch_iir & SDE_TRANSA_FIFO_UNDER)
-		intel_pch_fifo_underrun_irq_handler(dev_priv, TRANSCODER_A);
+		intel_pch_fifo_underrun_irq_handler(dev_priv, PIPE_A);
 
 	if (pch_iir & SDE_TRANSB_FIFO_UNDER)
-		intel_pch_fifo_underrun_irq_handler(dev_priv, TRANSCODER_B);
+		intel_pch_fifo_underrun_irq_handler(dev_priv, PIPE_B);
 }
 
 static void ivb_err_int_handler(struct drm_i915_private *dev_priv)
@@ -2123,13 +2123,13 @@ static void cpt_serr_int_handler(struct drm_i915_private *dev_priv)
 		DRM_ERROR("PCH poison interrupt\n");
 
 	if (serr_int & SERR_INT_TRANS_A_FIFO_UNDERRUN)
-		intel_pch_fifo_underrun_irq_handler(dev_priv, TRANSCODER_A);
+		intel_pch_fifo_underrun_irq_handler(dev_priv, PIPE_A);
 
 	if (serr_int & SERR_INT_TRANS_B_FIFO_UNDERRUN)
-		intel_pch_fifo_underrun_irq_handler(dev_priv, TRANSCODER_B);
+		intel_pch_fifo_underrun_irq_handler(dev_priv, PIPE_B);
 
 	if (serr_int & SERR_INT_TRANS_C_FIFO_UNDERRUN)
-		intel_pch_fifo_underrun_irq_handler(dev_priv, TRANSCODER_C);
+		intel_pch_fifo_underrun_irq_handler(dev_priv, PIPE_C);
 
 	I915_WRITE(SERR_INT, serr_int);
 }