xf86drmMode: introduce drmModeGetPropertyType

We already have drm_property_type_is, but it's needlessly complicated
and doesn't cover all use-cases (requires the caller to provide a
type).

Signed-off-by: Simon Ser <contact@emersion.fr>
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>
diff --git a/xf86drmMode.h b/xf86drmMode.h
index 7269678..4bde6e3 100644
--- a/xf86drmMode.h
+++ b/xf86drmMode.h
@@ -151,6 +151,11 @@
 	return property->flags & type;
 }
 
+static inline uint32_t drmModeGetPropertyType(const drmModePropertyRes *prop)
+{
+	return prop->flags & (DRM_MODE_PROP_LEGACY_TYPE | DRM_MODE_PROP_EXTENDED_TYPE);
+}
+
 typedef struct _drmModeCrtc {
 	uint32_t crtc_id;
 	uint32_t buffer_id; /**< FB id to connect to 0 = disconnect */