drm/i915: explicitly cast pipe -> cpu_transcoder

This makes sparse happy and also makes it a bit more obvious where we
pull off this trick - after all we're only allowed to do it eithe as a
default or on platforms where there is no disdinction between the pipe
and the cpu transcoder.
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_display.c

@@ -4966,7 +4966,7 @@ static bool i9xx_get_pipe_config(struct intel_crtc *crtc,
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	uint32_t tmp;
 
-	pipe_config->cpu_transcoder = crtc->pipe;
+	pipe_config->cpu_transcoder = (enum transcoder) crtc->pipe;
 	pipe_config->shared_dpll = DPLL_ID_PRIVATE;
 
 	tmp = I915_READ(PIPECONF(crtc->pipe));
@@ -5837,7 +5837,7 @@ static bool ironlake_get_pipe_config(struct intel_crtc *crtc,
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	uint32_t tmp;
 
-	pipe_config->cpu_transcoder = crtc->pipe;
+	pipe_config->cpu_transcoder = (enum transcoder) crtc->pipe;
 	pipe_config->shared_dpll = DPLL_ID_PRIVATE;
 
 	tmp = I915_READ(PIPECONF(crtc->pipe));
@@ -5953,7 +5953,7 @@ static bool haswell_get_pipe_config(struct intel_crtc *crtc,
 	enum intel_display_power_domain pfit_domain;
 	uint32_t tmp;
 
-	pipe_config->cpu_transcoder = crtc->pipe;
+	pipe_config->cpu_transcoder = (enum transcoder) crtc->pipe;
 	pipe_config->shared_dpll = DPLL_ID_PRIVATE;
 
 	tmp = I915_READ(TRANS_DDI_FUNC_CTL(TRANSCODER_EDP));
@@ -7051,7 +7051,7 @@ struct drm_display_mode *intel_crtc_mode_get(struct drm_device *dev,
 	 * Note, if LVDS ever uses a non-1 pixel multiplier, we'll need
 	 * to use a real value here instead.
 	 */
-	pipe_config.cpu_transcoder = intel_crtc->pipe;
+	pipe_config.cpu_transcoder = (enum transcoder) intel_crtc->pipe;
 	pipe_config.pixel_multiplier = 1;
 	i9xx_crtc_clock_get(intel_crtc, &pipe_config);
 
@@ -7881,7 +7881,8 @@ intel_modeset_pipe_config(struct drm_crtc *crtc,
 
 	drm_mode_copy(&pipe_config->adjusted_mode, mode);
 	drm_mode_copy(&pipe_config->requested_mode, mode);
-	pipe_config->cpu_transcoder = to_intel_crtc(crtc)->pipe;
+	pipe_config->cpu_transcoder =
+		(enum transcoder) to_intel_crtc(crtc)->pipe;
 	pipe_config->shared_dpll = DPLL_ID_PRIVATE;
 
 	/* Compute a starting value for pipe_config->pipe_bpp taking the source