drm/i915: set the right SDVO transcoder for CPT

v2: add a CPT-specific macro, make code cleaner
v3: fix commit message

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=41272
Cc: stable@kernel.org
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Keith Packard <keithp@keithp.com>

drivers/gpu/drm/i915/i915_reg.h

@@ -3303,10 +3303,10 @@
 /* or SDVOB */
 #define HDMIB   0xe1140
 #define  PORT_ENABLE    (1 << 31)
-#define  TRANSCODER_A   (0)
-#define  TRANSCODER_B   (1 << 30)
-#define  TRANSCODER(pipe)	((pipe) << 30)
-#define  TRANSCODER_MASK   (1 << 30)
+#define  TRANSCODER(pipe)       ((pipe) << 30)
+#define  TRANSCODER_CPT(pipe)   ((pipe) << 29)
+#define  TRANSCODER_MASK        (1 << 30)
+#define  TRANSCODER_MASK_CPT    (3 << 29)
 #define  COLOR_FORMAT_8bpc      (0)
 #define  COLOR_FORMAT_12bpc     (3 << 26)
 #define  SDVOB_HOTPLUG_ENABLE   (1 << 23)

drivers/gpu/drm/i915/intel_sdvo.c

@@ -1086,8 +1086,12 @@ static void intel_sdvo_mode_set(struct drm_encoder *encoder,
 		}
 		sdvox |= (9 << 19) | SDVO_BORDER_ENABLE;
 	}
-	if (intel_crtc->pipe == 1)
-		sdvox |= SDVO_PIPE_B_SELECT;
+
+	if (INTEL_PCH_TYPE(dev) >= PCH_CPT)
+		sdvox |= TRANSCODER_CPT(intel_crtc->pipe);
+	else
+		sdvox |= TRANSCODER(intel_crtc->pipe);
+
 	if (intel_sdvo->has_hdmi_audio)
 		sdvox |= SDVO_AUDIO_ENABLE;