include: replace unifdef-y with header-y

unifdef-y and header-y has same semantic.
So there is no need to have both.

Drop the unifdef-y variant and sort all lines again

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
diff --git a/include/drm/Kbuild b/include/drm/Kbuild
index bd3a1c2..ffec177 100644
--- a/include/drm/Kbuild
+++ b/include/drm/Kbuild
@@ -1,12 +1,14 @@
-unifdef-y += drm.h drm_sarea.h drm_mode.h
-unifdef-y += i810_drm.h
-unifdef-y += i830_drm.h
-unifdef-y += i915_drm.h
-unifdef-y += mga_drm.h
-unifdef-y += r128_drm.h
-unifdef-y += radeon_drm.h
-unifdef-y += sis_drm.h
-unifdef-y += savage_drm.h
-unifdef-y += vmwgfx_drm.h
-unifdef-y += via_drm.h
-unifdef-y += nouveau_drm.h
+header-y += drm.h
+header-y += drm_mode.h
+header-y += drm_sarea.h
+header-y += i810_drm.h
+header-y += i830_drm.h
+header-y += i915_drm.h
+header-y += mga_drm.h
+header-y += nouveau_drm.h
+header-y += r128_drm.h
+header-y += radeon_drm.h
+header-y += savage_drm.h
+header-y += sis_drm.h
+header-y += via_drm.h
+header-y += vmwgfx_drm.h