drm_hwcomposer: Make uevent listener standalone

1. DRM event listener doesn't work in this conditions, uevent blocks
   the thread and non-blocking select() doesn't make any sense.
   Remove DRM event handling for now.

2. UEvent listeren is common for all DrmDevices, therefore put it into
   ResourceManager class.

Signed-off-by: Roman Stratiienko <roman.o.stratiienko@globallogic.com>
diff --git a/drm/ResourceManager.cpp b/drm/ResourceManager.cpp
index c55d6b8..8baa4cb 100644
--- a/drm/ResourceManager.cpp
+++ b/drm/ResourceManager.cpp
@@ -70,6 +70,12 @@
     return -EINVAL;
   }
 
+  ret = uevent_listener_.Init();
+  if (ret) {
+    ALOGE("Can't initialize event listener %d", ret);
+    return ret;
+  }
+
   return 0;
 }