kms: full property registration infrastructure

property.rs: DrmProperty, PropertyRegistry with type-safe registration
  Range/Enum/Blob/Object property types
  ObjectType enum (CRTC/Connector/Plane)
  Properties filtered by object_id + object_type
  Register methods: register_range, register_enum, register_blob, register_object

This replaces the hardcoded synthetic property arrays in scheme.rs.
Compositors can now query properties dynamically per-object.

local/recipes/gpu/redox-drm/source/src/kms/property.rs

@@ -0,0 +1,101 @@
+use std::fmt;
+
+#[derive(Clone, Debug)]
+pub struct DrmProperty {
+    pub prop_id: u32,
+    pub name: String,
+    pub flags: u32,
+    pub prop_type: PropertyType,
+    pub object_id: u32,
+    pub object_type: ObjectType,
+}
+
+#[derive(Clone, Debug)]
+pub enum PropertyType {
+    Range { min: u64, max: u64, current: u64 },
+    Enum { values: Vec<(u64, String)>, current: u64 },
+    Blob { blob_id: u32 },
+    Object { current: u32 },
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub enum ObjectType {
+    Crtc,
+    Connector,
+    Plane,
+}
+
+#[derive(Clone, Debug)]
+pub struct PropertyRegistry {
+    properties: Vec<DrmProperty>,
+}
+
+impl PropertyRegistry {
+    pub fn new() -> Self {
+        Self { properties: Vec::new() }
+    }
+
+    pub fn register_range(&mut self, prop_id: u32, name: &str, flags: u32,
+                          obj_id: u32, obj_type: ObjectType,
+                          min: u64, max: u64, current: u64) {
+        self.properties.push(DrmProperty {
+            prop_id, name: name.to_string(), flags,
+            object_id: obj_id, object_type: obj_type,
+            prop_type: PropertyType::Range { min, max, current },
+        });
+    }
+
+    pub fn register_enum(&mut self, prop_id: u32, name: &str, flags: u32,
+                         obj_id: u32, obj_type: ObjectType,
+                         values: Vec<(u64, String)>, current: u64) {
+        self.properties.push(DrmProperty {
+            prop_id, name: name.to_string(), flags,
+            object_id: obj_id, object_type: obj_type,
+            prop_type: PropertyType::Enum { values, current },
+        });
+    }
+
+    pub fn register_blob(&mut self, prop_id: u32, name: &str, flags: u32,
+                         obj_id: u32, obj_type: ObjectType) {
+        self.properties.push(DrmProperty {
+            prop_id, name: name.to_string(), flags,
+            object_id: obj_id, object_type: obj_type,
+            prop_type: PropertyType::Blob { blob_id: 0 },
+        });
+    }
+
+    pub fn register_object(&mut self, prop_id: u32, name: &str, flags: u32,
+                           obj_id: u32, obj_type: ObjectType, current: u32) {
+        self.properties.push(DrmProperty {
+            prop_id, name: name.to_string(), flags,
+            object_id: obj_id, object_type: obj_type,
+            prop_type: PropertyType::Object { current },
+        });
+    }
+
+    pub fn properties_for_object(&self, obj_id: u32, obj_type: ObjectType) -> Vec<&DrmProperty> {
+        self.properties.iter()
+            .filter(|p| p.object_id == obj_id && p.object_type == obj_type)
+            .collect()
+    }
+
+    pub fn property_count(&self, obj_id: u32, obj_type: ObjectType) -> usize {
+        self.properties.iter()
+            .filter(|p| p.object_id == obj_id && p.object_type == obj_type)
+            .count()
+    }
+
+    pub fn find_property(&self, prop_id: u32) -> Option<&DrmProperty> {
+        self.properties.iter().find(|p| p.prop_id == prop_id)
+    }
+}
+
+impl fmt::Display for ObjectType {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            ObjectType::Crtc => write!(f, "CRTC"),
+            ObjectType::Connector => write!(f, "Connector"),
+            ObjectType::Plane => write!(f, "Plane"),
+        }
+    }
+}