kms/crtc: Find GAMMA_LUT property

To be used by the atomic backend to implement setting gamma ramps.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1488>

src/backends/native/meta-kms-crtc-private.h

@@ -28,6 +28,7 @@ typedef enum _MetaKmsCrtcProp
 {
   META_KMS_CRTC_PROP_MODE_ID = 0,
   META_KMS_CRTC_PROP_ACTIVE,
+  META_KMS_CRTC_PROP_GAMMA_LUT,
   META_KMS_CRTC_N_PROPS
 } MetaKmsCrtcProp;
 

src/backends/native/meta-kms-crtc.c

@@ -245,6 +245,11 @@ init_proporties (MetaKmsCrtc       *crtc,
           .name = "ACTIVE",
           .type = DRM_MODE_PROP_RANGE,
         },
+      [META_KMS_CRTC_PROP_GAMMA_LUT] =
+        {
+          .name = "GAMMA_LUT",
+          .type = DRM_MODE_PROP_BLOB,
+        },
     }
   };