drm/i915: Introduce an HAS_IPS() macro

Follow the trend and don't code conditions with platforms but with
features.

Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index b08d1f9..17d5c7a 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -3250,7 +3250,7 @@
 /* IPS only exists on ULT machines and is tied to pipe A. */
 static bool hsw_crtc_supports_ips(struct intel_crtc *crtc)
 {
-	return IS_ULT(crtc->base.dev) && crtc->pipe == PIPE_A;
+	return HAS_IPS(crtc->base.dev) && crtc->pipe == PIPE_A;
 }
 
 static void hsw_enable_ips(struct intel_crtc *crtc)
@@ -4069,7 +4069,7 @@
 		pipe_config->pipe_bpp = 8*3;
 	}
 
-	if (IS_HASWELL(dev))
+	if (HAS_IPS(dev))
 		hsw_compute_ips_config(crtc, pipe_config);
 
 	/* XXX: PCH clock sharing is done in ->mode_set, so make sure the old