drm/i915: Make ironlake_{enable,disable}_display_irq() static inlines

ironlake_{enable,disable}_display_irq() each just call
ilk_update_display_irq() so let's make them static inlines.

While at it s/ironlake/ilk/ to make things shorter, and a bit more
consistent with the ibx functions.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1448294777-13722-3-git-send-email-ville.syrjala@linux.intel.com
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/intel_fifo_underrun.c b/drivers/gpu/drm/i915/intel_fifo_underrun.c
index 7ae182d..48bd079 100644
--- a/drivers/gpu/drm/i915/intel_fifo_underrun.c
+++ b/drivers/gpu/drm/i915/intel_fifo_underrun.c
@@ -128,9 +128,9 @@
 					  DE_PIPEB_FIFO_UNDERRUN;
 
 	if (enable)
-		ironlake_enable_display_irq(dev_priv, bit);
+		ilk_enable_display_irq(dev_priv, bit);
 	else
-		ironlake_disable_display_irq(dev_priv, bit);
+		ilk_disable_display_irq(dev_priv, bit);
 }
 
 static void ivybridge_check_fifo_underruns(struct intel_crtc *crtc)
@@ -161,9 +161,9 @@
 		if (!ivb_can_enable_err_int(dev))
 			return;
 
-		ironlake_enable_display_irq(dev_priv, DE_ERR_INT_IVB);
+		ilk_enable_display_irq(dev_priv, DE_ERR_INT_IVB);
 	} else {
-		ironlake_disable_display_irq(dev_priv, DE_ERR_INT_IVB);
+		ilk_disable_display_irq(dev_priv, DE_ERR_INT_IVB);
 
 		if (old &&
 		    I915_READ(GEN7_ERR_INT) & ERR_INT_FIFO_UNDERRUN(pipe)) {