drm/uapi: Deprecate nonsense kms mode types

BUILTIN, CRTC_C, CLOCK_C, and DEFULT mode types are unused. Let's
refuse to generate them or accept them from userspace either. A
cursory check didn't reveal any userspace code that would depend
on these.

v2: Recommend DRIVER instead of BUILTIN (ajax)

Cc: Jose Abreu <Jose.Abreu@synopsys.com>
Cc: Adam Jackson <ajax@redhat.com>
Cc: Keith Packard <keithp@keithp.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Adam Jackson <ajax@redhat.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171115154504.14338-1-ville.syrjala@linux.intel.com
Reviewed-by: Jose Abreu <joabreu@synopsys.com>
diff --git a/include/drm/drm_modes.h b/include/drm/drm_modes.h
index 99dd815..71cbb10 100644
--- a/include/drm/drm_modes.h
+++ b/include/drm/drm_modes.h
@@ -242,8 +242,6 @@ struct drm_display_mode {
 	 * A bitmask of flags, mostly about the source of a mode. Possible flags
 	 * are:
 	 *
-	 *  - DRM_MODE_TYPE_BUILTIN: Meant for hard-coded modes, effectively
-	 *    unused.
 	 *  - DRM_MODE_TYPE_PREFERRED: Preferred mode, usually the native
 	 *    resolution of an LCD panel. There should only be one preferred
 	 *    mode per connector at any given time.
@@ -253,8 +251,11 @@ struct drm_display_mode {
 	 *  - DRM_MODE_TYPE_USERDEF: Mode defined via kernel command line
 	 *
 	 * Plus a big list of flags which shouldn't be used at all, but are
-	 * still around since these flags are also used in the userspace ABI:
+	 * still around since these flags are also used in the userspace ABI.
+	 * We no longer accept modes with these types though:
 	 *
+	 *  - DRM_MODE_TYPE_BUILTIN: Meant for hard-coded modes, unused.
+	 *    Use DRM_MODE_TYPE_DRIVER instead.
 	 *  - DRM_MODE_TYPE_DEFAULT: Again a leftover, use
 	 *    DRM_MODE_TYPE_PREFERRED instead.
 	 *  - DRM_MODE_TYPE_CLOCK_C and DRM_MODE_TYPE_CRTC_C: Define leftovers