disp:msm:sde: ensure HDR properties are updated during HPD

This patch fixes an issue where the HDR connector properties for
external displays were not being updated after a hot-plug event.

Change-Id: I78dbf00a103ab0bd361039eae2bac16ef9372e36
Signed-off-by: Steve Cohen <cohens@codeaurora.org>

msm/sde/sde_connector.c

@@ -2245,6 +2245,8 @@ static int _sde_connector_install_properties(struct drm_device *dev,
 	if (connector_type == DRM_MODE_CONNECTOR_DisplayPort) {
 		struct drm_msm_ext_hdr_properties hdr = {0};
 
+		c_conn->hdr_capable = true;
+
 		msm_property_install_blob(&c_conn->property_info,
 				"ext_hdr_properties",
 				DRM_MODE_PROP_IMMUTABLE,