drm/i915: Add support for integrated HDMI on G4X hardware.

This is ported directly from the userland 2D driver code.  The HDMI audio bits
aren't hooked up yet.

Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Dave Airlie <airlied@linux.ie>
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 4756e5c..563de18 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -664,6 +664,7 @@
 				 writel(upper_32_bits(val), dev_priv->regs + \
 					(reg) + 4))
 #endif
+#define POSTING_READ(reg)	(void)I915_READ(reg)
 
 #define I915_VERBOSE 0
 
@@ -760,6 +761,7 @@
 			IS_I945GM(dev) || IS_I965GM(dev) || IS_GM45(dev))
 
 #define I915_NEED_GFX_HWS(dev) (IS_G33(dev) || IS_GM45(dev) || IS_G4X(dev))
+#define SUPPORTS_INTEGRATED_HDMI(dev)	(IS_G4X(dev))
 
 #define PRIMARY_RINGBUFFER_SIZE         (128*1024)