hal: Update controller during DP device disconnection.

When MST is connected, first DP device gets assigned as AUX_DIGITAL,
second one gets assigned as AUX_DIGITAL1, both have stream/mst index
as 0 and 1 respectively and controller as 0. During disconnection,
controller was not being updated due to which both device disconnection
resulted in disconnection of AUX_DIGITAL1, and AUX_DIGITAL was not getting
disconnected. When SST is connected, previous AUX_DIGITAL was being
used with stream/mst_index as 1 for SST which is not proper resulting in
graph_start failures.

Change-Id: I0da96d996a1f36c8014c347e9d65d705d8e761f6
(cherry picked from commit 612766463a8e531cb650a75f7df02d5e3d851c82)
diff --git a/hal/AudioDevice.cpp b/hal/AudioDevice.cpp
index 1ea826f..4e750d4 100644
--- a/hal/AudioDevice.cpp
+++ b/hal/AudioDevice.cpp
@@ -1752,6 +1752,7 @@
             AudioExtn::get_controller_stream_from_params(parms, &controller, &stream);
             param_device_connection.device_config.dp_config.controller = controller;
             param_device_connection.device_config.dp_config.stream = stream;
+            dp_controller = controller;
             dp_stream = stream;
             AHAL_INFO("plugin device cont %d stream %d", controller, stream);
         }